Gottfried Leibniz: One of the Great renaissance men of Western thought - A Critical Estimate of Leibniz’s theory of Truth

Dr. Pushpa Rani Prasad

by Pushpa Rani Prasad
Dr. Pushpa Rani Prasad, a Commissioned Principal, working at S.P. Mahila College, Dumka, Jharkhand (India) writes in both English and Hindi. She is a pioneer of modern vision and her voice for modern Indian women is miracle and outstanding.

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Abstract:

According to Leibniz’s theory of truth, the nature of truth consists of connection or inclusion of a predicate in a subject. Leibniz uses his apparently self-evident principles such as the principle of sufficient reason, the law of contradiction, the identity of indiscernible and predicate-in-notion theory of truth to develop a remarkable philosophical system that provides an intricate and through account of reality. Ultimately, Leibniz’s universe contains only God and non-composite immaterial, soul-like entities called “monads”. In this article, I have tried to critically examine his concept of truth, the principle of ‘sufficient reason’ and the principle of contradiction. I have tried to point out that there is no consistent account of the principle of ‘sufficient reason’ because of differences of meaning, which Leibniz gives to the expression ‘sufficient reason’.

Leibniz’s theory of truth:

Leibniz has defined truth in terms of inclusion or containment, which is evident from his following statement:

“In every affirmative true proposition, necessary or contingent, universal or singular, the concept of predicate is included in that of the subject, praedicatum inest subjecto.”¹

Leibniz means to say that in the case of a true proposition, the concept of predicate is included in that of the subject.

He has also defined truth in another way. He says that a true proposition is one which is either an identical proposition or reducible to one.

Superficially, this appears quite different from the previous definition, but the only difference is that in the present definition, Leibniz is calling attention to the fact that the inclusion of the concept of the predicate in that of the subject is not always obvious, but often has to be shown. To understand what Leibniz is saying here, it is necessary first of all to realize that when he speaks of an identical proposition, he does not mean only propositions of the form ‘A is A’ - e.g. ‘A man is a man’; he also means propositions of the form “AB is A” - e.g. ‘A white man is white’. This is obviously related to what Leibniz has said about truth in terms of inclusion; e.g., he could have said that in the case of the proposition ‘A white man is white’ the concept of the predicate, whiteness is included in that of the subject. In such a case, the inclusion is manifest or evident; however, there are many cases in which the inclusion is concealed or implicit. Such implicit inclusion is “shown by the analysis of terms, by substituting for one another definitions and what is defined”.²

Leibniz means that in the case of true proposition “Every man is rational” the inclusion of the concept of rationality in that of man is only implicit; however, it can be made explicit by substituting for “man” its definition “rational animal”, so that we get the identical proposition “Every rational animal is rational”. It is in this way that a true proposition is ‘reduced’ to an identical proposition.

Necessary truth and contingent truth:

According to Leibniz in the case of necessary truths or truths of reasoning, its reason or explanation can be discovered by analysis of the notions or concepts. Thus truths of reason are necessary propositions in the sense that they are either themselves self-evident propositions or reducible thereto. All truths of reason are necessarily true, and their truth rests on the principle of contradiction. To take an example given by Leibniz, we cannot deny the proposition that the equilateral rectangle is a rectangle without being involved in contradiction.

Contingent truths or truths of fact, on the other hand, are not necessary propositions. Their opposites are conceivable, and they can be denied without logical contradiction. The proposition, for example, that John Smith exists is not a necessary but a contingent proposition. It is, indeed, logically and metaphysically inconceivable that John Smith should not exist while he is existing. A true existential statement that John Smith actually exists is a contingent proposition, a truth of fact. We cannot deduce it from any a priori self-evident truth; we know its truth a posteriori: But if John Smith actually exists, there must be a sufficient reason for his existence; that is, if it is true to say that John Smith exists, there must be a sufficient reason why it is true to say that he exists. Truths of fact, then, rest on the principle of sufficient reason.

Truths of reason embrace the sphere of the possible, while truths of fact embrace the sphere of existential. When a true proposition asserts existence of a subject, it is a truth of fact, a contingent proposition, and not a truth of reason. However, there is one exception to the rule that existential propositions are truths of fact. For the proposition that God exists is a truth of reason or necessary proposition, and denial of it involves for Leibniz a logical contradiction. However, apart from this one exception, no truth of reason asserts existence of any subject.

We find that Leibniz has employed the two principles – the Principle of Contradiction and the Principle of Sufficient Reason in the service of his distinction between the truths of reasoning and truths of fact, that is, between necessary truths and contingent truths.

Before a critical examination of the concept of truth and Leibniz’s distinction between necessary truths and contingent truths, it would be pertinent to define the Principle of Contradiction and the Principle of Sufficient Reason. The Principle of Contradiction states simply that ‘a proposition cannot be true and false at the same time, and that therefore A is A and cannot be not A’. The Principle of Sufficient Reason in its classic form is simply that nothing is without a reason (nihil est sine ratione) or there is no effect without a cause. Leibniz suggests that the claim that nothing takes place without a sufficient reason means that nothing happens in such a way that it is impossible for someone with enough information to give a reason why it is so and not otherwise. According to Leibniz, the Principle of Sufficient Reason must actually follow from the predicate-in-notion principle, for if there were a truth that had no reason, then there would be a proposition whose subject did not contain the predicate, which is a violation of Leibniz’s conception of truth.

Now I will discuss a difficulty that is presented by Leibniz's theory of truth. This theory seemed to imply that there are no truths that are not necessary. It was pointed out earlier that Leibniz defines a true proposition as one which is either an identical proposition or is reducible to an identical proposition. The problem is, that he offers exactly the same definition of a necessary truth. An alternative definition of necessary truth - namely, that a necessary truth is one whose opposite implies a contradiction - also causes difficulties, this time in connection with Leibniz's theory of truth as it is stated in terms of containment. Parkinson points put that, as Leibniz saw, “'If, at a given time the concept of predicate is in the concept of subject, then how, without contradiction and impossibility, can the predicate not be in the subject at that time?”³

Speaking of this problem and his attempts to solve it, Leibniz says that “A new and unexpected light finally arose in a quarter where I least hoped for it-namely, out of mathematical considerations of the nature of infinite”.⁴ The solution was this: in the case of necessary truths, the inclusion of the concept of predicate in that of the subject is something that we human beings can prove. That is, we can show in a finite number of steps that the concept of the predicate is included in that of the subject; or we can, in finite number of steps, reduce to an identical proposition the proposition whose truth is to be established. But in the case of contingent truths, we cannot do this. The concept of the predicate is indeed in that of the subject, but this can never be demonstrated, nor can the proposition ever be reduced to an equation or identity. Instead, the analysis proceeds to infinity. According to Leibniz it is only God who can see the connection of terms or the inclusion of the predicate in the subject, for he sees whatever is in the series.

Parkinson is of the view that this solution raises problems of its own. First, what exactly was the light that arose ‘out of mathematical considerations of the nature of the infinite’? It is clear from Leibniz’s writings that he holds that ‘rest’ can be considered as a special case of motion - motion which is infinitely  little, or which vanishes into rest. Similarly, a contingent truth can be regarded as a special case of the inclusion of the concept of the predicate in that of the subject-namely, where the analysis of the concepts that would be necessary to provide a proof is infinite.

Leibniz says that mathematics suggested the solution, but he also knew that it suggested an objection to it. The difficulty in question involves the irrational numbers. Leibniz often compares the distinction between necessary and contingent truths with that between rational and irrational numbers, or, as he says, between numbers that are commensurable and those that are incommensurable or “surd”. He explains his difficulty by reference to incommensurable ratios or proportions. He says that an incommensurable ratio is not expressible, which is to say that it cannot be expressed by a finite series of numbers, the series required is infinite. Correspondingly, the analysis of a contingent truth is infinite. Leibniz also points out that in mathematics, we can establish demonstrations by showing that the error involved is less than any assignable error. As this is so, it may seem that human beings also will be able to comprehend contingent truths with certainty. Leibniz, however, says that this is beyond our powers. We can indeed establish proofs of the kind described - i.e. proofs in which the error involved is less than any assignable error - in the case of incommensurable ratio. But in the case of contingent truths, not even thus is conceded to created mind.

But what entitles Leibniz to be sure about this? After all, there was a time when it was thought that human being could not give mathematical proofs of the kind to which Leibniz refers; yet such proofs were found. Why, then, should it be beyond human powers to find comparable proofs of contingent truths?

Leibniz has also distinguished necessary from contingent truths in a different way. Leibniz says that necessary truths are based on principle of contradiction and on the possibility and impossibility of essences themselves. But the reasons that one can bring for a contingent truth are based on that which appears the best among several things which are equally possible; such truths (unlike necessary truths) are based on the free will of God or of creatures. Thus Leibniz has distinguished between necessary and contingent truths by reference to the different reasons that can be brought for them. In a paper for Samuel Clarke, Leibniz calls the principles involved those of contradiction and sufficient reason respectively, and says that “what is necessary is so by its essence because the opposite implies a contradiction; but the contingent which exists owes its existence to the principle of what is best, the sufficient reason for things.”⁵

Leibniz’s use of the terms here is confusing, in that he often uses the term “principle of sufficient reason” in such a way as to apply to absolutely all truths, necessary as well as contingent. In this use, he says that the principle of sufficient reason is that by which we consider that no fact can be real or existing and no proposition can be true unless there is a sufficient reason, why it should be thus and not otherwise. This version of the principle of sufficient reason, which applies both to necessary and contingent truths, adds little to what has already been seen of Leibniz's theory of truth. All that Leibniz has added to this is the statement that to do so is to give a sufficient reason for the truth of the proposition. However, we have seen that Leibniz calls the principle of sufficient reason to distinguish contingent truth, (whose principle it is) from necessary truth (whose principle is that of contradiction). In this sense of the principle of sufficient reason, the reasons that one can bring for a contingent truth are based on that which is or appears the best among several things which are equally possible, and they are related to the free will of God or of creatures. Or, as Leibniz says elsewhere the connection between the predicate and the subject of a contingent truth is not a necessary one, but depends on an assumed divine decree and on free will.

I pass now to a question which is no less fundamental. This is the question of analytic and synthetic judgement and their relation to necessity. As regards the range of analytic judgements, Leibniz held that all the propositions of logic, Arithmetic and Geometry are of this nature, while all existential propositions, except the existence of God, are synthetic. As regards the meaning of analytic judgements, it will assist us to have in our minds some of the instances, which Leibniz suggests. We shall find that these instances suffer from one or other of two defects. Either the instances can be easily seen to be not truly analytic - this is the case, for example, in Arithmetic and Geometry - or they are tautologous, and so not properly propositions at all. Thus, Leibniz says, on one occasion that primitive truths of reason are identical, because they appear only to repeat the same thing, without giving any information. Among the instances given by Leibniz are ‘A’ is ‘A’, ‘The equilateral rectangle is a rectangle’ etc. Most of these instances assert nothing; the remainder can hardly be considered the foundations of any important truth. These propositions are clearly tautological. The propositions of Arithmetic, as Kant discovered are one and all synthetic. In the case of Geometry, which Leibniz also regards as analytic, the opposite view is even more evident. Kant, by pointing out that mathematical judgements are both necessary and synthetic, prepared the way for the view that this is true of all judgements. It must be confessed that, if all propositions are necessary, the notion of necessity is shorn of most of its importance. Bertrand Russel in his book A Critical Expositions of the Philosophy of Leibniz writes:

“Whatever view we adopt, however, as regards the necessity of existential propositions, it must be admitted that arithmetical propositions are both necessary and synthetic, and this is enough to destroy the supposed connection of necessary and the analytic” ⁶.

CONCLUSION:

It is clear from the above discussions that there is no consistent account of the principle of sufficient reason because of differences of meaning which Leibniz gives to the expression ‘sufficient reason’.

In saying that contingent truths depend on the free will of God and necessary truths do not, Leibniz was opposing Descartes, who said that the will of God is involved even in necessary truths, and also Spinoza, who took the view that God cannot be said to act from freedom of will. In sum, Leibniz holds (against Spinoza) that there are contingent truths which depend of the free will of God and of creatures. He also holds (against Descartes) that Gods free will is not arbitrary, God acts for the sake of the good which is independent of his will, and his actions are in accordance with eternal truths which his will does not produce.

Regarding the question of analytic and synthetic judgement and their relation to necessity Leibniz has held that all propositions of Logic, Arithmetic and Geometry are analytic. It appear to me that the view of Bertrand Russel that arithmetical propositions are both necessary and synthetic is correct.

*   *   *

Reference:

1. Parkinson, G.H.R.: Philosophy and Logic, In The Cambridge Companion to Leibniz; ed. By Nicholas Jolley, Cambridge University Press, 1995, p-200.
2. Ibid : Page-202
3. Ibid : Page-203
4. Ibid : Page-203
5. Ibid : Page-207
6. Russel, Bertrand: A Critical Exposition of the Philospphy of Leibniz; Forgotten Books, 2013, p-24.

Setu, September 2018

A Critical Estimate of Hume's view on Causation

David Hume: ‘With Hume, the Modern Philosophy of Causation Begins’

Dr. Pushpa Rani Prasad

by Pushpa Rani Prasad

Abstract:

The idea of causation is one of the threadbare problems of philosophy and has been discussed both by the philosophers and the scientists from the dim past to the present age. Its root goes as far back as to Aristole. In the Cartesian philosophy, as in that of the scholastics, the connection of cause and effect was supposed to be necessary, as logical connections are necessary. The first really serious challenge to this view came from Hume. It has rightly been said that with Hume the modern philosophy of causation begins. In the opinion of Hume, no quality of any object which we consider a cause can be the origin of the idea of cause for there is no discoverable quality which is common to all objects. Hume points out that the idea of causation is derived from the relations such as contiguity, priority of time, constant conjunction and necessary connection. In his opinion the relation of cause and effect does not depend much on the relations of contiguity, succession and constant conjunction. The central theme of Hume’s entire argument is to point out how experience gives rise to the idea of necessary connection. He concludes that necessity is something which exists in mind, not in objects. It is nothing but that determination of thought to pass from causes to effects and from effects to causes, according to their experienced union. Belief in causation is due to custom-born association. Necessary connection is not an affair of reason but of imagination.

hUME’S VIEW ON CAUSATION:

The oldest view on the issue of causation is that of the rationalists. According to them causation is a necessary connection between cause and effect, which is true for all the time. Hume's view of causation keeps an important place in the history of philosophy. Causation has been viewed by Hume both as a philosophical relation and a natural relation. Considering as a philosophical relation cause has been defined by Hume as:

"An object precedent and contiguous to another, and where all the objects resembling the former are placed in like relations of precedency and contiguity to those objects that resemble the latter".¹

Causation as a natural relation has been defined by Hume as “A cause is an object precedent and contiguous to another and so united with it that the idea of one determines the mind to form the idea of the other, and the impression of the one to form a livelier idea of the other”.²

Hume divides all the objects of human inquiry into 'relations of ideas' and 'matters of fact'. The former includes those ideas which are either intuitively or demonstratively certain. The relations of matters of fact are identity, situation in time and place and causation. Hume says that all kinds of reasoning consist in nothing but a comparison and a discovery of those relations, either constant or inconstant, which two or more objects bear to each other. This comparison may be made either when both the objects are present to the senses, or when neither of them is present, or when only one. When both the objects are present to the senses along with the relation, we call this perception rather than reasoning. In it there is no exercise of thought but admission of impression through the organs of senses only. In the case of comparisons of identity and relation of time and place the mind is concerned with what is actually there. Observations we make concerning identity and time and place cannot be treated as reasoning, since in none of them mind can go beyond what is immediately present to the senses.

The relation of cause-effect informs us of existences and objects which we do not see or feel. So, this relation needs philosophical analysis. Hume proceeds to examine the idea of cause by searching for impression or impressions from which it is derived. In the opinion of Hume, no quality of any object which we consider a cause can be the origin of the idea of cause for there is no discoverable quality which is common to all objects.

So, the idea that of causation must be derived from some relation among objects which Hume now endeavours to discover.

The relations which Hume discovers are:

(i)                Contiguity

(ii)              Priority of time (the cause prior to effect)

(iii)           Necessary connection.

(i)    Contiguity:

 Hume finds that whatever objects are considered as cause and effects, are contiguous and nothing can operate in a time or place which is ever so little removed from those of its existence. Though distant objects may sometimes seem productive of each other, they are commonly found upon examination to be linked by a chain of causes, which are contiguous among themselves and to the distant objects. Hume, thus, considers the relation of contiguity as essential to that of causation.

(ii)   Priority of time (succession):

The second relation which we find between cause and effect is that of 'priority of time'. It is generally observed that in the cause and effect series, cause comes earlier in time and the effect follows later in time. Succession in time is always observed. For instance, when we switch on, the lamp is lighted. Here the cause ‘switch on’ comes prior to the effect the 'lightening of lamp'.

It would be untrue to say that Hume lays great emphasis on contiguity and on temporal succession as essential elements of causal relation. He says,

"An object may be contiguous and prior to another without being considered as its cause. There is a Necessary Connection to be taken into consideration; and that relation is of much greater importance than any of the other two above-mentioned".³

Hume points out that sounds and smells, passions and volitions cannot properly be said to have shapes or positions at all, but do enter into causal relationship. It is not, therefore, his final opinion that spatial contiguity is an essential part of causation as regards the question of time relation between cause and effect, Hume never clears up. He gives what purports to be an argument to show that effect must follow cause in time. 

(iii)  Necessary Connection:

Hume finds that the relation of cause and effect depends not in the least on known qualities of objects considered as cause. The relations of contiguity and succession have already been regarded as imperfect and unsatisfactory.

The two questions which Hume now proceeds to examine are:

(1)     "First, for what reason we pronounce it necessary that everything whose existence has a beginning should also have a cause?

(2)     Secondly, why we conclude, that such particular causes must necessarily have such particular effects; and what is the nature of that inference we draw from the one to the other, and of the belief we repose in it?

The first question is concerning the necessity of a cause. Hume says it is a general maxim in philosophy that whatever begins to exist must have a cause. This is commonly taken for granted in reasoning without any proof given or demanded. Hume asserts that idea of necessity is neither intuitively nor demonstratively proved to be certain. Hume says that as we cannot derive the opinion of the necessity of a cause to every new production from knowledge or any scientific reasoning, that opinion must necessarily arise from observation and experience. The next question then, should naturally be, how experience gives rise to such a principle? Hume thinks that the answer to this question will be found perhaps in answering the second question.

Nature of Causal Inference:

According to Hume when we infer effects from causes, we must establish the existence of these causes which can be done only by immediate perception of our memory or senses. It is impossible for us to carry on our inferences in infinitum. So all the reasoning concerning causes and effects are originally derived from some impressions. In causal inference we find that when we have the perception of cause or of effect only, its correlative is inferred in idea. Causal inferences, thus, contain a present perception either of sense or memory, and an idea reached by inference.

In the opinion of Hume, the ultimate cause of the impressions which arise from senses is perfectly inexplicable by human reason and that such a question is not in any way material to the present purpose. As regards ideas of memory Hume says, "Since therefore the memory is known neither by the order of its complex ideas, nor the nature of its simple ones; it follows that the difference betwixt it and the imagination lies in its superior force and vivacity".⁴

Hume says that it is merely the force and liveliness of the perception which lays the foundation of that reasoning which we built upon it, where we trace the relation of cause and effect. Hume says that the belief or assent which always attends the memory and senses is nothing but vivacity of those perceptions they present.

Now Hume proceeds to examine the inference which we draw from cause (impression), to effect (idea). Hume is of the view that one does not in fact need to survey particular objects or make any penetration into the real essences of things when we discover causal connections. The discovery is not derived from any such penetration.

So, separation of cause and effect implies no absurdity and self-contradiction. Effect being distinct from its cause can never be discovered in it, any conception of it a priori must be entirely arbitrary.

Had causation been a logical relation, then the contradictory of every true proposition which asserted a causal connection would be self-contradictory. In that case the proposition which asserted the existence either of general or of particular causal connections would have been analytic, which is not a fact. It is very likely that the course of Nature may change, and our previously experienced result may be attended with different or contrary effects. He cites the example of a body, falling from the clouds that it may resemble snow in all other aspects, but has the taste of salt or feelings of fire. Thus, Hume rightly thinks that it is only by experience that the validity of any synthetic proposition can be determined. It is therefore by experience only, that we can infer the existence of one object from that of another.

Hume advances a general description of the experience that is causal inference. Explaining the nature of experience Hume says that we remember to have had frequent instances of the existence of one species of objects; and also remember that the individuals of another species of objects have always attended them and have existed in a regular order of contiguity and succession with regard to them. For example, "we remember to have seen that species of object we call flame, and to have felt that species of sensation we call heat. We likewise call to the mind their constant conjunction in all past instances. Without any farther ceremony, we call the one cause and the other effect, and infer the existence of one from that of the other".⁵

Thus, a new relation between cause and effect has been discovered. This relation is their constant conjunction. Contiguity and succession are not sufficient to make us pronounce any two objects to be cause and effect, unless we perceive, that these two relations are preserved in several instances. Constant conjunction implies that like objects have always been placed in like relations of contiguity and succession.

Hume points out that the newly discovered relation of a constant conjunction seems to advance us very little in our way. In his opinion what we learn not from one object, we can never learn from a hundred, which are all of the same kind, and are perfectly resembling in every circumstance. It is clear that constant conjunction cannot by itself be the origin of the idea of necessary connection. But Hume points out that we make causal inference, which consists in a "transition from an impression or memory of one object to the idea of another which we call its cause or effect, whenever we have experience of constant conjunction.

Hume says that if reason determined us to make the transition it would proceed upon that principle "that instances, of which we have had no experience, must resemble those, of which we have had experience, and that the course of nature continues always uniformly the same".⁶

Hume now considers all those arguments upon which such a proposition may be supposed to be founded and which must be derived either from knowledge or probabilities. Hume says that there can be no demonstrative arguments to prove that those instances, of which we have had no experience resemble those, of which we have had experience. It is not an analytic proposition; whose contradictory is inconceivable. A change in course of nature is perfectly conceivable. Probability, in its distinction from demonstration, does, indeed, rest on an appeal to experience, but it concerns only those happenings in regard to which there is a conflict of experience.

It is clear that 'reason' can never show us the connection of one object with another, though aided by experience, and the observation of their constant conjunction in all past instances. Giving a solution of this dilemma Hume says that when the mind passes from an idea or impression of one object to the idea or belief of another, it is not determined by reason, but by certain principles, which associate together the idea of these objects, and unite them in imagination. He says:

“Thus, in transition from an impression of one object to an idea of another, it is the imagination which is operating, not understanding. It is custom and not reason, habit and not evidence, which is at work”.⁷

Custom or habit here operates in and through the laws of association; and it is upon this associative union of ideas that the inference rests. We find that from the constant conjunction the objects acquire a union in the imagination and when an impression of one becomes present to us, we immediately form idea of its usual attendant.

The idea of Necessary Connection:

After explaining the manner in which we reason beyond our immediate impressions and conclude that such particular causes must have such particular effects, Hume returns to examine the question raised earlier viz. what is our idea of necessity, when we say that two objects are necessarily connected together. As there is no idea that is not derived from some impression, Hume proceeds to find some impression that gives rise to this idea of necessity when the two objects are supposed to be placed in causal relation. It is perceived that they are contiguous in time and place and that the object we call cause precedes the other we call effect. The relation of constant conjunction also does not help much and does not give rise to a new idea.

Hume has also examined the question concerning the power and efficacy of causes which has caused much disputes both among ancient and modern philosophers. Hume observes that efficacy, agency, power, force, energy, necessity and productive quality are all nearly synonymous and tries to find impression from which the idea of power or efficacy is originally derived.

Thus, according to Hume, if two objects are presented to us, of which one is the cause and other the effect, it is plain from any one instance we never arrive at the idea of cause and effect, of a necessary connection of power, of force, of energy and of efficacy. When we observe several instances, in which the same objects are always conjoined together, we immediately conceive a connection between them and begin to draw an inference from one to the other. This multiplicity of resembling instances, therefore, constitutes the very essence of power or connection, and is the source from which the idea of it arises. The repetition of perfectly similar instances can never alone give rise to an original idea, different from what is found in any particular instance which is also evident from the fundamental principle that all ideas are copied from impression.

Hume says after we have observed the resemblance in a sufficient number of instances, we immediately feel a determination of the mind to pass from one object to its usual attendant, and to conceive in a stronger light upon account of that relation. This determination is the only effect of the resemblances, and therefore must be same with power or efficacy, whose idea is derived from resemblance. Necessity then is the effect of this observation and is nothing but an internal impression of the mind, or a determination to carry our thoughts from one object to another. There is no impression conveyed by our senses which can give rise to that idea. It must, therefore, be derived from some internal impression or impression of reflection. There is no internal impression but that propensity which custom produces, to pass from an object to the idea of its usual attendant. So the necessity is something which exists in mind, not in objects. Necessity is nothing but that determination of the thought to pass from causes to effects and from effects to causes, according to their experienced union.

Hume's commentators have assumed that Hume questions the validity of the causal maxim. But he cannot be accused of denying causation; rather he was concerned with defining it properly. The question is not whether there are causal relations. Hume's discussions concern only the grounds upon which the causal belief rests. All that Hume denies is that there is any secret tie between cause and effect due to which one can necessarily produce the effect. Hume finds a substitute for this alleged power which he calls 'determination of the mind'.

Some modern thinkers have appreciated Hume's views. The concept of regular succession given by Hume can be observed by differentiating two phrases, “after this" and "because of this". The meaning of "because of this", is entirely different from 'after this'. The logical positivists maintain that actually one observes regularity or uniformity of sequence between the events. They would therefore agree with Hume that the only thing which distinguishes a purely temporal sequence i.e. "this after that ", from causal "this because of that", is the greater regularity of the latter.

Russell also believes that from practical point of view causation is same as the varying sequence. It means that Russell accepts Hume's view of causation as regular sequence.

Smith remarks that if necessary connection is not revealed in one instance, it is also not revealed in any number of similar instances. He says, "It is precisely the similarity of the instances which constitutes the uniformity, and which therefore rules out the possibility of more being revealed by additional instances than is revealed in single instance".⁸

Because nothing is given in one instance, repetition or uniformity cannot be made the basis of inference to the future either demonstrative or probable. Smith holds, therefore, that what one requires is that the enlargement of experience which will supply us, what neither single instance not the mere repetition of similar instances can yield.

What Hume had done in connection with the idea of necessary connection is to have redefined the idea. By redefining the idea as a feeling of connection in our mind, he saves the idea from the fate of being condemned as meaningless. It follows from the redefined idea that the traditional notion of necessary connection is rejected. The traditional meaning is shown to have no application, since it had no corresponding impression. The most important conclusions which Hume arrives at as regards causal relation are that belief in causation is due to custom-born association and that necessary connection between cause and effect is never perceived. It is not an affair of reason but of imagination.

We find that Bertrand Russell has supported Hume's view. In his book 'History of western philosophy' he writes: “So far as physical sciences are concerned, Hume is wholly in the right, such propositions as 'A causes B' are never to be accepted, and our inclination to accept them is to be explained by the habit and association”.⁹

A.J. Ayer is also of the opinion that causal connection belongs to the class of synthetic propositions. He writes “We have indeed, no a priori ground for either accepting or rejecting the doctrine that every event is causally connected with every other, but there are good empirical grounds for rejecting it".¹⁰

It was recognized by Hume that when we look towards external objects we are never able to discover any power or necessary connection. There is, Hume says, nothing in a number of instances, different from any single instance, which is supposed to be exactly similar, except only that after a repetition of similar instances the mind is carried by habit, upon the appearance of an event to except its usual attendant, and to believe that it will exist. This connection, therefore, which we feel in the mind, this customary transition of the imagination from an object to its usual attendant, is the sentiment or impression from which we form the idea of necessary connection.

Conclusion:

Thus, in my opinion at least this much is important about Hume, that his main interest is neither to provide a psychological nor any objective account of this principle; rather his main effort seems to present a conceptual analysis of causation. It still remains a doubtful proposition whether or not he has unfolded the idea of causation as it lies within the mind, or has he explained it adequately as a natural law? The main reason of all the misunderstandings is the lack of proper appraisal of Hume's position. While providing this account, Hume was very much cautious that he was not going to propound this stupid doctrine that an event can take place without any cause, rather he simply wanted to point out that the notion of causal necessity can neither be known through perception nor through inference, rather it is only the product of our faith, imagination and habit. He intends to dethrone the concept of causation as a necessary connection because the idea of cause has been the bedrock of traditional cosmology, theology and ethics. In fact, Hume's attempt is quite praiseworthy to the extent that he has evoked the scientists and philosophers to think this problem a fresh on empirical light. And this has produced a good effect on the logical empiricists like Russell, Carnap, Ayer etc. Blanshard has pointed out that "Russell and Wittgenstein have almost returned to Hume's conclusion".¹¹

Hume has deduced the conclusion keeping his view on his basic premise that "all the perceptions of human mind resolve themselves into two distinct kind, which I shall call "impressions" and "ideas" and this part of Hume's attempt is still a landmark in the field of recent philosophy which drew the attention of large number of philosophers. Challenging the traditional concept of causation as a necessary connection, Hume attempted a re­examination of the very idea of causation for a correct appraisal. And here again, Hume seems to be the precursor of the logical empiricism whose job is also the same.

Reference:

1. Hume, David:            A Treatise of Human Nature; Ed. by L.A. Selby-Bigge, The Clarendon Press, Oxford-1958, p-170.

2. Ibid: p-170.

3. Ibid: p-77.

4. Ibid: p-85.

5. Ibid: p-87.

6. Ibid: p-89

7. Ibid: Abstract, p-16 quoted in The Philosophy of David Hume, by N.K. Smith, p-375.

8. Smith, N.K.:  The Philosophy of David Hume, London, Macmillan & Co. Ltd., 1964, p-394.

9. Russell, Bertrand:      History of Western Philosophy; George Allen & Unwin Ltd., London, 1961, pp-642-643

10. Ayer, A.J.:   Languate, Truth and Logic; Victor Gollancz, London, 1967, p-151.

11. Blanshard, Brand:    Reason and Analysis, George Allen & Unwin Ltd., London, 1962, p-445.

 

About the Writer:

Dr. Pushpa Rani Prasad, a Commissioned acting Principal working at S.P. Mahila College, Dumka, Jharkhand (India) writing in both English and Hindi. She is a pioneer of modern vision and her voice for modern Indian women is miracle and outstanding.

Setu, August 2018

Descartes’ Dictum Cogito, Ergo Sum: The Relation of Cogito to Sum

Dr. Pushpa Rani Prasad, a Commissioned acting Principal working at S.P. Mahila College, Dumka, Jharkhand (India) writing in both English and Hindi. She is a pioneer of modern vision and her voice for modern Indian women is miracle and outstanding.

Dr. Pushpa Rani Prasad

Abstract

The attempt to put knowledge on certain foundation is historically associated with the philosophy of Descartes.  The most important question that has recurred most frequently regarding Descartes’ dictum ‘Cogito, ergo sum’ is that whether the proposition ‘I think, therefore I am’ is or is not an inference. According to Descartes, by saying cogito, ergo sum, he does not logically (syllogistically) deduce sum from cogito but rather perceives intuitively, the self-evidence of sum. But, there are several passages in the ‘Discourse and Principles’ that cause problems for the above view of Descartes. Philosophers differ on the exact relation of cogito to sum. Bernard Williams has defended the view that it is a kind of inference, though not syllogistic in form. On the other hand, in a recent paper Jaakko Hintikka has expressed the view that the word cogito serves to express the performatory character of Descartes’ insight. In this article, I have also examined Peter Markie’s view that it is self-evident Intuition/Immediate Inference Interpretation. In this article, I have tried to clear up the relation of cogito to sum.

The Relation of Cogito to Sum

Descartes employed methodic doubt with a view to discovering whether there was any indubitable truth. Though he regarded mathematics as the paradigm of knowledge, he knew that its ‘a priori truths’ are not indubitable because it was possible that a malignant demon should deceive him even with respect to those matters of which he was most certain. But he found that there was one proposition which was capable of escaping the demon’s reach. This was his famous dictum the ‘Cogito, Ergo Sum’ – ‘I think, therefore I am’.

Descartes writes:

“But I have convinced myself that there is absolutely nothing in the world, no sky, no earth, no minds, no bodies. Does it now follow that I too do not exist? No, if I convinced myself of something then I certainly existed. But there is a deceiver of supreme power and cunning who is deliberately and constantly deceiving me; and let him deceive me as much as he can, he will never bring it about that I am nothing so long as I think and that I am something. So after considering everything very thoroughly, I must finally conclude that this proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind.”¹

At first sight, the cogito certainly seems to be an inference. Descartes’ dictum really express an inference is suggested by the particle ergo. In many respects it seems plausible to think that it does express a logical inference. Its logical form seems quite easy to define. In the sentence ‘I think’, an individual receives an attribute; for a modern logician it is therefore of the form “B(a)”. In the sentence ‘I am’ or ‘I exist’ the same individual is said to exist. Such type of views has been expressed by many philosophers. Gassendi claimed that ‘ambulo, ergo sum’, ‘ I walk, therefore I am’, is as good an inference as cogito, ergo sum.

In his reply to Gassendi, Descartes denies that ambulo, ergo sum is comparable with ‘cogito, ergo sum’. The reasons he gave are not very clear. Descartes’ remark is perhaps that although the inferences ‘ambulo, ergo sum’ and ‘cogito, ergo sum’ are parallel, their premises are essentially different. Ambulo is not an indubitable premise in the way cogito may be claimed to be.

In many passages Descartes seems to deny that by saying cogito, ergo sum he does logically (syllogistically) deduce sum from cogito. According to him, “he rather perceives intuitively (by a single act mental vision) the self-evidence of sum”.

Descartes writes:

“When someone says ‘I think, therefore I am’, he does not deduce his existence from his thinking by means of a syllogism, but, by the mind’s simple act of inspection, sees it something that is self-evident. This is apparent from the fact that, if he deduced it by means of a syllogism, he would first have had to know the major premise, “Everything that thinks is or exists”. But that, on the contrary, has been learned from the individuals awareness of himself – that he cannot be thinking unless he exists. For it is the nature of our mind to form general propositions from knowledge of particulars”.²

Jaakko Hintikka is of the view that the relation of the two parts of the ‘cogito, ergo sum’ cannot be a logical inference in the ordinary sense of the word. According to him, in Descartes’ argument the relation of cogito to sum is not that of premise to a conclusion. He says that, “their relation is rather comparable with that of a process to its product. The indubitability of my own existence results from my thinking of it almost as the sound of music results from playing it or light in the sense of illumination (lux) results from the presence of a source of light (lumen)³. Regarding the function of the word cogito in Descartes’ sentence as well as his motives in employing it, Hintikka says that, “it serves to express the performatory character of Descartes’ insight; it refers to the “performance” (to the act of thinking) through, which the sentence ‘I exist’ may be said to verify itself. For this reason, it has a most important function in Descartes’ sentence. It cannot be replaced by any arbitrary verb. The performance (act) through which the existential self-verifiability is manifested cannot be any arbitrary human activity, contrary to what Gassendi claimed. It cannot be an act of walking or an act of seeing”.⁴

Peter Markie is of the view that the answer to this problem is that:

“Descartes intuits the self-evident proposition that he thinks and simultaneously infers that he exists. His knowledge that he thinks is intuitive in the primary sense of being self-evident and entirely non-inferential; his knowledge that he exists is intuitive in the extended sense of being immediately inferred from the simultaneously intuited premise that he thinks”.⁵

Markie has referred to many statements of Descartes, which support this interpretation. Descartes presents intuition and deduction as his only sources of certainty in the Regulae. According to Descartes, deduction is the inference of something as following necessarily from some other propositions with certainty. Intuition is the faculty by which we gain the initial certainties that make deduction possible. Intuition is distinguished from deduction by the fact that it does not involve a movement of thought through a series of inferences and by its immediate self-evidence.

According to Descartes, when we immediately infer a conclusion from an intuited self-evident premise, we are not aware of any movement of thought through series of premises, so we may describe our knowledge of the conclusion as intuitive. No extended series of intuitions lead us to the conclusion, there is just one mental act in which the self-evident premise is intuited and the immediate conclusion is drawn.

Descartes’ remarks in the Discourse and Principles further support this interpretation. In Discourse Descartes says, “And observing that this truth ‘I am thinking therefore I exist’ was so firm and sure that all the most extravagant suppositions of the skeptics were incapable of shaking it, I decided that I could accept without scruple as the first principle of the philosophy I was seeking”.⁶

In the Principles Descartes writes:

“For it is a contradiction to suppose that what thinks does not, at the very time it is thinking, exist. Accordingly, this piece of knowledge – I am thinking; therefore, I exist – is the first and most certain of all to occur to anyone who philosophizes in an orderly way”.⁷

In each passage, Descartes presents his immediate inference from his thought to his existence as a single piece of knowledge, it is the first principle of his philosophy. His point seems to be that in one act of intuition, he grasps the premise and immediately infers the conclusion.

Peter Markie has called this interpretation “The self-evident Intuition/Immediate inference interpretation”. But, Descartes’ arguments in some passages cause problems for the above interpretation. In one of the passages in the Principles, Descartes says that prior to knowing that he thinks and therefore he exists, he must know, not only what thought, existence and certainty are, but also the general proposition that it is impossible for what thinks not to exist. His point seems to be that his inference from his thought to his existence uses the general proposition as a suppressed premise. It is not, ‘I am thinking, therefore I exist’, it is ‘I am thinking and whatever is thinking must exist, therefore I exist’.

But in his comment to Mersenne in Second Replies, Descartes explicitly denies that his inference from his thought to existence is a syllogism using the general premise that whatever thinks must exist. He repeats the same point in response to one of Gassendi’s objections.

If we modify our interpretation so that Descartes’ inference uses the general premise that whatever thinks must exist, we shall be in conflict with his replies to Mersenne and Gassendi, but if we do not modify our interpretation in this way, how are we to account for his claim in the Principles, that prior to knowing that we think and therefore exist, we must know whatever thinks must exist.

There are several passages that conflict with the self-evident Intuition/Immediate Inference Interpretation. Peter Markie suggests that the Self-evident Intuition/Immediate Inference interpretation can be modified to account for some, though not all, of the problematic passages. To develop the new interpretation, he has examined two basic concepts of Descartes' epistemology, his concept of certainty and his concept of reasonable belief. Descartes' epistemology contains two degrees of epistemic appraisal. One is the top standard of certainty and the other is a lesser degree of justification, which Descartes describes as highly probable or very reasonable belief. All the beliefs that meet the demands of certainty for him, such as his belief about his thought and existence in the Second Meditation, are also very reasonable, but some of his very reasonable beliefs, such as his sensory evidenced beliefs about the external world in the First Meditation, are not certain for him. Which degree of epistemic appraisal a belief meets is determined by his evidence for the belief. The sensory evidence Descartes has for his external world beliefs in the First Meditation makes those beliefs very reasonable but not certain. The evidence Descartes has for his belief in the existence in the Second Meditation makes that belief both very reasonable and certain. When a belief is self-evident, Descartes' evidence for it consists of his act of clearly and distinctly perceiving it. When a belief is not self-evident, Descartes' evidence for it consists of those belief that constitute his reason for believing it. The difference between what is merely very reasonable and what is certain is that Descartes has slight reason to doubt the former. A hypothesis gives Descartes a reason to doubt one of his beliefs just when it is a possibility he has not ruled out and it indicates how his belief might be false despite his evidence. The hypothesis that he is dreaming and that some God deceives him are possibilities he has· not ruled out in the First Meditation and they indicate how his very reasonable beliefs about the external world might be false despite his sensory evidence for them.

In Peter Markie’s view, relative to these points we can better understand Descartes' claim to certainty about his thought and existence. Descartes' claim has two parts:

(i)      He has evidence for these beliefs that makes them very reasonable.

(ii)    That evidence resists even the slightest, most exaggerated reasons for doubt, so that his beliefs are certainties.

In the light of above points, the Self-Evident Intuition/Immediate Inference Interpretation may be modified. The first thing Descartes must do is explain what makes his beliefs in his thought and existence very reasonable. This is where his frequent appeals to clear and distinct perception and an immediate inference from his thought to existence come into play. Descartes takes his belief in his thought to be very reasonable because the proposition that he thinks is a self-evident one he clearly and distinctly perceives to be true. His act of clear and distinct perception is the "evidence" that makes his belief that he thinks very reasonable. The same may be said of his other beliefs about his mental state. His belief in the existence is very reasonable, because he immediately infers it from a very reasonable belief about his mental state.

Yet, what makes these beliefs so reasonable as to be certain? Descartes' answer is that he has no reason to doubt them. Now his observation about how reasons for doubt just affirm his thought and existence comes into play. In Second Meditation Descartes says the Deceptive God Hypothesis and Dream Hypothesis do not give him a reason to doubt his beliefs that he thinks and exists; for they entails them and so fails to indicate how they might be false despite his clear and distinct perception.

If we modify our interpretation in the above way Descartes’ claim appears to be consistent.

Now we will see how the above modified interpretation deals with the passages that cause problems for the initial one. Our modified interpretation easily avoids one of the problems we have examined. Our initial interpretation is inconsistent with Descartes' claim, in the Meditations and Replies, that some clear and distinct perceptions, specifically ones of very simple mathematical truths, are made doubtful by the Deceptive God Hypothesis. Our modified interpretation is consistent with Descartes' claim. It says all clear and distinct perceptions are very reasonable and only those that concern our thought and existence are certain. The difference between the certain clear and distinct perceptions and the merely very reasonable ones is that the former resist reasons for doubt like Deceptive God Hypotheses. Such reasons for doubt do not indicate how our beliefs in our thought and existence might be false despite the clear and distinct perceptions that support them.

Another problem concerns whether Descartes' inference from his thought to his existence is immediate or a syllogism. We have seen a passage in the Principles insists on the importance of a prior knowledge of the general principle that whatever thinks must exist. The way to account for this passage is to pay close attention to what Descartes says he must know prior to knowing his thought and existence. He must know that what thinks must exist, and he must also know what knowledge, thought, existence and certainty are. His point surely is not that all this information must be added to his inference from thought to existence to bridge the gap between his initial premise and his conclusion. He does not need to add definitions of thought, existence and certainty to his argument to get from "I think" to "I exist." His point is this: he must have some of this information to understand the propositions that he thinks and that he exists and the rest to understand his account of why they are certain for him. He cannot understand the propositions, unless he knows what thought and existence are. He cannot understand his account of why they are certain for him unless he knows what certainty is. He cannot understand his account of why they are certain unless he knows that what thinks must exist; for part of his account is that his belief that he thinks immediately entails, and so makes reasonable, his belief that he exists. Descartes does not offer the general principle that what thinks must exist as a suppressed premise in his inference from his thought to his existence. He offers it as something he must know to understand why his thought and existence are certain for him. Moreover, it is sufficient that this general principle is reasonable for Descartes; it need not be certain. When Descartes claims to be certain of his thought and existence in the Second Meditation, he does not offer that claim to certainty - I am certain about my thoughts and existence as a certainty. He presents it and his explanation of why it is true as reasonable beliefs about his epistemic state.

Thus, we see that Peter Markie’s modified version of the self-evident Intuition/Immediate Inference Interpretation avoids the textual problems with the initial version. The above arguments clearly show that the proposition Cogito, Ergo Sum is not an inference.

Conclusion

 The above discussions conclude my survey of the relation of Cogito to sum. We have seen that there is no settled agreement among the philosophers on the exact relationship of Cogito to sum. Bernard Williams in his paper ‘The Certainity of the Cogito’ contends that the relation of cogito to the sum is a kind of inference. Hintikka has raised a number of valid points in his analysis of Descartes’ cogito as a performatory utterance. In this article I have examined Peter Markies’s view that it is self-evident Intuition/Immediate Inference interpretation. This interpretation can be modified in the light of two basic concepts of Descartes’ epistemology, his concept of certainty and his concept of reasonable belief in such a way that avoids the problematic passages. His modified interpretation is consistent with Descartes’ claim that all clear and distinct perception are very reasonable and only those that concern our thought and existence are certain. I support the above view. The arguments given by Markie are very convincing. In my opinion the relation of Cogito to the sum is not an inference but a self-evident intuition/Immediate Interference Interpretation.

Descartes’ claim to certainty about his thought and existence is central to his general program in epistemology. He wants to answer skepticism, and he wants to do so within foundationalism, the view that all our knowledge begins with some self-evident beliefs which are not evidenced by any others but yet provide our justification for all the rest we know. His claim to certainty about his thought and existence is the initial move in his attempt to define the set of self-evident beliefs. Descartes also thinks that his claim to certainty of his thought and existence plays an important role in his metaphysics. He says that the real value of his dictum ‘I think, therefore I am’ is that it can be used to establish that this ‘I which is thinking is an immaterial substance with no bodily element’. This is a continuing theme in Descartes’ philosophy.

But we find that there are some underlying philosophical issues that Descartes leaves. Philosophers have objected to his account of how he gains the very reasonable belief that he thinks to begin with. He says he clearly and distinctly perceives that he thinks. His concept of clear and distinct perception is the least clear and distinct concept in philosophy. He never adequately explains what this mental vision is or why apprehending a proposition by it is sufficient to make belief in the proposition very reasonable. Descartes leaves us wondering exactly how our beliefs about our mental state and existence become reasonable. Descartes is open to a criticism nicely stated by A.J. Ayer.

“What Descartes thought that he had shown was that the statements that he was conscious, and that he existed, were somehow privileged, that, for him at least, they were evidently true in a way which distinguished them from any other statements of fact. But this by no means follows from his argument. His argument does not prove that he, or anyone, knows anything. It simply makes the logical point that one sort of statement follows from another”.⁸

Descartes needs both parts of his explanation of his certainty. He needs an account of what makes his beliefs in his thought and existence very reasonable and an account of why those reasonable beliefs resist every reason for doubt. It may be said in Descartes favour that the issues which he has raised makes his position interesting and important. Thus, we see that the main interpretive issues have been settled, but the philosophical issues remain as part of Descartes’ legacy to us.

Reference:

1.      Cottingham, John and Robert Stoothoff & Dugald Murdoch: The Philosophical Writings of Descartes, Cambridge University Press, 1984, Vol.-II, p.p.-16-17.

2.      Descartes, Rene: Replies to the Second set of Objections in the Decartes, A collection of critical essays. Edited by Willis Doney, Anchor Books, Double Day & Company Inc., New York, 1967, p-90.

3.      Hintikka, Jaakko: Cogito, Ergo Sum Inference or Performance; In Descartes: A Collection of Critical Essays, Edited by Willis Doney, Anchor Books, Double Day & Company Inc., New York, 1967, p-122.

4.      Ibid, p-123.

5.      Markie, Peter: The Cogito and Its importance; In The Cambridge Companion to Descartes, Edited by John Cottingham, Cambridge University Press, 1992, p.p.-145-146.

6.      Cottingham, John and Robert Stoothoff & Dugald Murdoch: The Philosophical Writings of Descartes, Cambridge University Press, 1984, Vol.-I, p.-127.

7.      Ibid, p.-195

8.      Ayer, A.J.: ‘I Think, Therefore I Am’, In Descartes: A Collection of Critical Essays, Edited by Willis Doney, Anchor Books, New York, p-82.

Setu, June 2018