Objective communication—the principal aim of languages of any kind—meets with its greatest measure of success in science and art, which can both be precise, and therefore immune to misunderstanding born of vagueness or ambiguity, by giving specific expression to ideas. But, paradoxically, in order to reach specificity science and art must be developed along two opposite directions: in the first technical terminology replaces imagery-bearing words, in the second images are cultivated to the utmost. The scientist's procedure is entirely justified. For (...) it is undeniable that words are often misleading. because they are clouded with different images in the minds of different people. (shrink)

To bring clearly before the mind what is meant by class and to distinguish this notion from all the notions to which it is allied, is one of the most difficult and important problems of mathematical philosophy.”When Russell wrote this in 1903, he could illustrate the difficulty of the problem by his own confusing attempt at a solution. He was able to demonstrate the importance of classes for mathematical philosophy in his later work: the definition of cardinal number as a (...) class of classes similar to a given class served him as a cornerstone for the derivation of mathematics from logic. (shrink)

This essay proposes to differentiate between science and philosophy on the evidence that the truth of scientific, or, more generally, empirical, statements is perspectival whereas the truth of a philosophical statement is not. A perspectival truth depends upon a perspective in the sense that it may no longer be acceptable after the point of view which determines a perspective has been changed to another. Accordingly, the admission of perspectival truth requires the existence of alternative perspectives. The existence of alternative perspectives (...) does not mean that every statement which is true in one of them is false in another. Some statements, to be called perspectivally invariant, remain true regardless of the perspective. But the admission of perspectival truth requires at least one statement to be true in one perspective but false in an alternative perspective. Two perspectives, no matter how different in other respects, will not be called alternative unless they involve perspectival truth. The point is important. For no one denies that perspectives differ with regard to their heuristic value, i.e. no one would deny that a certain point of view may lead us to findings which from a different point of view might remain indiscernible and therefore undiscovered. But the opponents of perspectival truth and of alternative perspectives argue, with W. R. Dennes, that once a truth has been established the same finding can be acknowledged by a true statement in any other perspective although the acknowledgment may call for a restatement in a different idiom or language. The issue is between the admission of perspectival truth, on the one hand, and the contention of interperspectival translatability of truth, on the other. (shrink)

This essay is a refutation of Hume on causal inference. The decisive point of the refutation is that Hume's argument is invalid unless it is assumed, contrary to his own relational theory of time, that mere difference in dates can affect the course of nature. In the preliminary discussion of sections II and III the words “cause,” “effect,” and “causal relation” are employed in a nontechnical sense, which is exemplified in such statements as “Fire causes heat”, “Lightning and thunder are (...) causally related”, “When one turns the steering wheel to the right, the effect is that the car moves to the right”, and so on. But in order to forestall rebuttals in defense of Hume one needs a greater precision in terminology as well as in conception of causality. Section IV aiming at precision gives a statement of the principles of causality which is in accordance with the position of modern science. An examination of this statement shows that the validity of causal inference must be accepted along with a relational theory of time. A comment on causal inference in relation to induction brings the discussion to a close. (shrink)