The original stimulus for the choice of this topic was a book on intellectual history. One of the most brilliant authors in this field, Carl Becker, claims that the most important event in the intellectual history of modern time was the shift in the place of logic in science. According to Becker, the high esteem for logic which the scientist had in the age of St. Thomas Aquinas and through all the Middle Ages declined in the period of Galileo and Newton. But at that time this decline was not yet fully understood. “The marriage of fact and reason” as Becker expresses himself “proved to be somewhat irksome in the nineteenth century and was altogether dissolved in the twentieth century.” The modern, twentieth century, physicist lives in an “atmosphere, which is so saturated with the actual that we can easily do with a minumum of theoretical” … “We have long since learned not to bother much with reason and logic.” To describe the spirit of twentieth century physics which emphasizes facts and minimizes reason Becker says: “Experiments seem to show that an electron may, for reasons best known to itself, be moving at two orbits at the same time. To this point Galileo's common sense method of noting the behavior of things, of sticking close to the observable facts has brought us. It has at last presented us with a fact that common sense repudiates.”

Formal implication is usually represented by symbolization such as ‘(x) φx ⊃ Ψx,’ which may be read, “for all values of ‘x’, φx (materially) implies Ψx.” If the values of the variable ‘x’, in ‘φx’ and ‘Ψx’ be ‘x1’ ‘x2’ ‘x3’, etc., then … ‘φx’ formally implies ‘Ψx’ if and only if, whatever values of ‘x’, ‘xn’, be chosen, ‘φxn’ materially implies ‘Ψxn’ …

However, this still leaves it doubtful which of two possible interpretations of expressions having the form ‘(x) φx ⊃ Ψx’ is to be taken as correct. … It means one thing to say, “Every existent having the property φ … has also the property Ψ,” and it means quite a different thing to say, “Every thinkable thing which should have the property φ must also have the property Ψ.” The second of these holds only when having the properly φ logically entails having the property Ψ; when ‘Ψx’ is deductible from ‘φx’. … The first of them, however, holds not only in such cases … but also in every case where among existent things, one property is universally accompanied by another. (C. I. Lewis, An Analysis of Knowledge and Evaluation, pp. 217–8. I am responsible for the italicizing of the sentence, otherwise the italics follow Lewis.)

As everyone who has looked into almost any philosophical journal within the last year is aware, Charles Morris has written a book on signs. (Signs, Language and Behavior, Prentice-Hall, Inc., 1946, hereafter abbreviated “SLB”) More precisely, he has elaborated a strain of thought found in his very earliest writings. A first, partial culmination of these ideas is his monograph Foundations of the Theory of Signs (FTS). Since the publication of FTS, Morris has conducted experiments relative to human sign behavior. SLB, I believe, is a revision and expansion of FTS to take into account new material supplied by these experiments and increased insight into the nature of behavior psychology. For Morris now asserts explicitly, what before he only hinted: that “Semiotic thus becomes a part of the empirical science of behavior, and can utilize whatever principles and predictions the general theory of behavior has attained or can attain.” (SLB p. 19)

Mr. Thomas Storer does not believe that a science of signs is of basic importance to philosophy, for philosophy, he holds, is not a formal or a factual science but an activity of clarifying meaning and building linguistic systems. I should like to defend the relevance to philosophy of a science of signs even when philosophy is so conceived, and then to question this conception of philosophy itself.

Everyone is agreed that mankind today finds itself virtually swimming in crises. The typical discussion of every world problem is so fraught with a sense of urgency, so steeped in the hyperbole of danger, that the discussions would be funny were they not so tragic.

I am greatly obliged to Mr. Williams and the editor for the republication of numerous passages from my recent book. I especially appreciate Mr. Williams' contribution of a magnificent answer to those of my critics who contend that my book is largely devoted to belaboring a straw man because our generation no longer holds any of the views I attack. Even though my views are both misquoted and out of context in his presentation, I must say that they never looked better to me than in the light of his criticism. On the other hand, it would certainly never have occurred to me to reply to an effusion of this sort except for the editors' request for comment. If I failed in my little book to make clear my position, as I obviously did in the case of Mr. Williams, I see small prospect of doing so in the few paragraphs here at my disposal. Since the essays to which he objects originally appeared in a popular magazine which, I believe, is known for the rigor of its editorship, at least so far as clarity is concerned, Mr. Williams' inability to understand them are the more disturbing. I will give only a few examples.

I want to commend the article, “Studies in the Logic of Explanation,” Philosophy of Science, April, 1948, by Hempel and Oppenheim. However, there are two points in the article that have been treated in a manner incompatible with the general attitude taken by the authors and, I believe, they are mistaken in these two rather essential matters. The first concerns the relationship between emergents and prediction. The second concerns the relationship between “evidence” or sense data and law.

Like a number of other authors, Miller uses the term “emergent” interchangeably with “unpredictable” and employs it as a property term, i.e., in contexts of the form “Event E is emergent.” As we showed in our article, however, predictability and unpredictability as well as emergence are relations; they can be predicated of an event only relatively to some body of information. Thus, a lunar eclipse is predictable by means of information including (a) data on the locations and speeds, at some particular time, of the celestial bodies involved, and (b) the laws of celestial mechanics plus certain principles of optics; it is unpredictable on the basis of, say, (b) alone. Consequently, the phrase “Event E is unpredictable” is incomplete, and hence meaningless, in much the same sense as the expression “Straight line l is parallel.” Similar observations apply to the term “emergent,” which is frequently used to characterize events which, in a sense examined in detail in our article, are not explainable by a micro-structure theory.

1. In his paper “On Denoting” Russell points out what he calls a puzzle every satisfactory theory of denoting will have to solve. Of the three sentences

1. (A) George IV. wished to know whether Scott was the author of Waverley

2. (B) Scott is the author of Waverley

3. (C) George IV. wished to know whether Scott was Scott the first two, (A) and (B), are presumably true, while the third, (C), is presumably false. The reason given for considering this arrangement of truth values a puzzle is (1) that the ‘is’ in (B) signifies identity; (2) that the proper name ‘Scott’ and the descriptive phrase ‘the author of Waverley’ denote the same object; and that, therefore, (3) if the latter is replaced by the former in the true sentence (A), the resulting sentence, (C), should again be true. Yet (C) is false, or, as one also says, the context considered is nonextensional with respect to this replacement.