POSITIVISM AS LEADING PSYCHOLOGICAL MOVEMENT FOR LOGICAL JUDGEMENT
"For a consideration of any dispute about a matter of any taste will show that there can be disagreement without formal contradiction, and that in order to alter another man's opinions, in the sense of getting him to change his attitude, it is not necessary to contradict anything that he asserts. Thus, if one wishes to affect another person in such a way as to bring his sentiments on a given point into accordance with one's own, there are various ways in which one may proceed. One may, for example, call his attention to certain facts that one supposes him to have overlooked; and, as I have already remarked, i believe that much of what passes for ethical discussion is a proceeding of this type. It is, however, also possible to influence other people by a suitable choice of emotive language; and this is the practical justification for the use of normative expressions of value. At the same time, it must be admitted that if the other person persists in maintaining his contrary attitude, without however disputing any of the facts, a point is reached at which the discussion can go further. And in that case there is no sense in asking which of the conflicting views is true. For, since the expression of a value judgement is not a proposition, the question of truth or falsehood does not here arise.
In such cases as these one does indeed arrive at something that approaches a definition in use; but there are other cases of philosophical analysis in which nothing even approaching a definition is either provided or sought. Thus, when Professor Moore suggests that to say that "existence is not a predicate" may be a way of saying that "there is some very important difference between the way in which 'exist' is used in such a sentence as 'Tame tigers exist' and the way in which 'growl' is used in 'Tame tigers growl,'" he does not develop his point by giving rules for the translation of one set of sentences into another. What he does is to remark that whereas it makes good sense to say "All tame to say "All tame tigers exist" of "Most tame tigers exist." Now this may seem a rather trivial point for him to make, but in fact it is philosophically illuminating. For it is precisely the assumption that existence is a predicate that gives plausibility to "the ontological argument"; and the ontological argument is supposed to demonstrate the existence of a god. Consequently Moore by pointing out a peculiarity in the use of word "exist" helps to protect us from a serious fallacy; so that his procedure, though different from that which Russell follows in the theory of descriptions, tends to achieve the same philosophical end.
I maintain in this book that it is not within the province of philosophy to justify our scientific or common-sense beliefs; for their validity is an empirical matter, which cannot be settled by a priori means. At the same time, the question of what constitutes such a justification is philosophical, as the existence of "the problem of induction" shows. Here again, what is required is not necessarily a definition. For although I believe that the problems connected within induction can be reduced to the question of what is meant by saying that one proposition is good evidence for another, I doubt if the way to answer this is to construct a formal definition of "evidence". What is chiefly wanted, I think, is an analysis of scientific method, and although it might be possible to express the results of this analysis in the form of definitions, this would not be an achievement of primary importance. And here I may add that the reduction of philosophy to analysis needs not to be incompatible with the view that its function is to bring to light "the presuppositions of science." For if there are such presuppositions, they can no doubt be shown to be logically involved in the applications of scientific method, or in the use of certain scientific terms.
In saying that the philosophy is concerned with each of the sciences, in a manner which we shall indicate, we mean also to rule out the supposition that philosophy can be ranged alongside the existing sciences, as a special department of speculative knowledge. Those who make this supposition cherish the belief that there are some things in the world which are possible objects of speculative knowledge and yet lie beyond the scope of empirical science.
But this belief is a delusion. There is no field of experience which cannot, in principle, beyond the power of science to give. We have already gone some way to substantiate this proposition by demolishing metaphysics; and we shall justify it to the full in the course of this book.
With this we complete the overthrow of speculative philosophy. We are now in a position to see that the function of philosophy is wholly critical. In what exactly does its critical activity consist?
One way of answering this question is to say that it is philosopher's business to test the validity of our scientific hypotheses and everyday assumptions. But this view, though very widely held, is mistaken. If a man chooses to doubt the truth of all the propositions he ordinarily believes, it is not in the power of philosophy to reassure him. The most that philosophy can do, apart from seeing whether his beliefs are self consistent, is to show what are the criteria which are used to determine the truth or falsehood of any given proposition: and then, when the sceptic realises that certain observations would verify his propositions, he may also realize that he could make those observations, and so consider his original beliefs to be justified. But in such a case one cannot say that it is philosophy which justifies his beliefs. Philosophy merely shows him that experience can justify them. We may look to the philosopher to show us what we accept as constituting sufficient evidence for the truth of any given empirical proposition. But whether the evidence is forthcoming or not is in every case a purely empirical question.
If anyone thinks that we are here taking too much for granted, let him refer to the chapter on "Truth and Probability," in which we discuss how to validity of synthetic propositions is determined. He will see there that the only sort of justification that is necessary of possible for self-consistent empirical propositions is empirical verification. And this applies just as much to the laws of science as to the maxims of common sense. Indeed there is no difference in kind between them. The superiority of the scientific hypothesis consists merely in its being more abstract, more precise, and more fruitful. And although scientific objects such as atoms and electrons seem to be fictitious in a way that chairs and tables are not, here, too, the distinction is only distinction of degree. For both these kinds of objects are known only by their sensible manifestations and are definable in terms of them.
One may attempt to deduce the preposition which one is required to prove either from a purely formal principle or from an empirical principle. In the former case one commits the error of supposing that from a tautology it is possible to deduce a proportion about a matter of fact; in the latter case one simply assumes what one is setting out to prove. For example, it is often said that we can justify induction by invoking the uniformity of nature, or by postulating a "principle of limited independent variety." But, in fact, the principle of uniformity of nature merely states, in a misleading fashion, the assumption that past experience is a reliable guide to the future; while the principle of limited independent variety pre-supposes it.
We shall see, when we come finally to settle the conflict between idealism and realism, that his actual conception of the relationship between material things and sense-contents was not altogether accurate. It led him to some notoriously paradoxical conclusions, which a slight emendation will enable us to avoid. But the fact that he failed to give a completely correct account of the way in which material things are constituted out of sense-contents does not invalidate his contention that they are so constituted. On the contrary, we know that it must be possible to define material things in terms of sense-contents, because it is only by the occurrence of certain sense-contents that the existence of any material thing can ever be in the least degree verified. And thus we see that we have not to enquire whether a phenomenalist "theory of perception" or some other sort of theory is correct, but only what form of phenomenalist theory is correct. For the fact that all causal and representative theories of perception treat material things as if they were unobservable entities entitles us, as Berkeley saw, to rule them out a priori. The unfortunate thing is that, in spite of this, he found it necessary to postulate God as an unobservable cause of our "ideas"; and he must be criticised also for failing to see that the argument which he uses to dispose of Locke's analysis of a material thing is fatal to his own conception of the nature of the self, a point which was effectively seized upon by Hume.
But first of all we ought, perhaps, to justify our assumption that the object of a "theory of truth" can only be to show how propositions are validated. for it is commonly supposed that the business of the philosopher who concerns himself with "truth" is to answer the question "What is truth?" and that is is only an answer to this question that can fairly be said to constitute a "theory of truth."
It may be objected here that we are ignoring the fact that it is not merely propositions that can be said to be true of false, but also statements and assertions and judgements and assumptions and opinions and beliefs. But the answer to this is that to say that a belief, or statement, or a judgement, is true is always an elliptical way of ascribing truth to a proposition, which is believed, of stated, or judged. Thus, if I say that the Marxist's belief that capitalism leads to war is true, what I am saying is that the proposition, believed by Marxists, that the capitalism leads to war is true; and the illustration holds good when the word "opinion" or "assumption," or any of the others in the list, is substituted for the word "belief." And, further, it must be made clear that we are not hereby committing ourselves to the meta-physical doctrine that propositions are real entities. Regarding classes as a species of logical constructions, we may define a proposition as a class of sentences which have the same intentional significance for anyone who understands them. Thus, the sentences, "I am ill," "Ich bin krank," "Je suis malade," are all elements of the proposition "I am ill." And what we have previously said about logical constructions should make it clear that we are not asserting that a proposition is a collection of sentences, but rather than to speak about a given proposition is a way of speaking about certain sentences, just as to speak about sentences, in this usage, is a way of speaking about particular signs.
Reverting to the analysis of truth, we find that in all sentences of the form "p is true," the phrase "is true" is logically superfluous. When, for example, one says that the proposition "Queen Anne is dead" is true, all that he is saying is that Queen Anne is dead.
This point seems almost too obvious to mention, yet the preoccupation of philosophers with the "problem of truth" shows that they have overlooked it. Their excuse is that references to truth generally occur in sentences whose grammatical forms suggest that the word "true" does stand for a genuine quality or relation. And a superficial consideration of these sentences might lead one to suppose that there was something more in the question "What is truth?" than a demand for the analysis of the sentence "p is true." But when one comes to analyse the sentences in question, one always finds that they contain sub-sentences of the form "p is true" or "p is false," and that when they are translated in such a way as to make these sub-sentences explicit, they contain no other mention of truth.
"What makes a proposition true or false?" And this is a loose way of expressing the question “With regard to any proposition p, what are the conditions in which p (is true) and what are the conditions in which not-p?" in other words, it is a way of asking how propositions are validated. and this is the question which we were considering when we embarked on our digression about the analysis of truth."
In chapter exploring critique of ethics and theology A.J.Ayer explores synthetic propositions and it comes to the conclusion that before it justifies views on all synthetic propositions saying that they are empirical hypotheses one more objection has to be met. "This objection is based on the common supposition that our speculative knowledge is of two stint kinds-that which relates to question of empirical fact, and that which relates to question of value. (...) "Statements of value", which is both satisfactory in itself and consistent with our general empiricist principles. We shall set ourselves to show that in so far as statements of value are significant, they are ordinary "scientific" and that in so far as they are not scientific, they are not in the literal sense significant, but are simply expressions of emotions which can be neither true nor false."
All above is either direct quotation from the book or rephrased points that I found of the most value in my study of Investigative Journalism research into psychological part of judgement.Language, Truth and Logic by Alfred Jules Ayer, (1967)
