Philosophers are often praised for their insight even if they are found wanting in their powers of analysis. The noble edifices of thought raised by the famous have been reduced to more or less noble ruins, if we consider what disintegrating, analytical time and tide have done to the weaker members of the structures. Some of the palaces of thought even seem to stand without any foundations. Yet they stand. They are admired no longer for their utility or for their massiveness, but for the beauty of their conception. Their conception is said to represent the insight of their authors.

In the Prologue to the third book of Gargantua, Francois Rabelais compares his own predicament to that of the philosopher Diogenes of Sinope during the seige of Cornith. “I held it not a little disgraceful”, he confides, “to be only an idle spectator of so many valorous, eloquent and warlike persons, who in the view and sight of all Europe act this notable interlude or tragi-comedy, and not exert myself and contribute thereunto this nothing, my all, which remained for me to do”.

Some of the objections most frequently raised against the thesis of physicalism can be summarized as follows:

(V) The notions of the biological and social sciences, as e. g. organic whole and Gestalt, means and ends, leadership and hierarchical order, the entire structure and meaning of these scientific systems, are of a type essentially different from those of physics. Consequently they can not be expressed by means of the mathematical language used by physics, and it is “logically impossible” to reduce these sciences to physics.

The effort here is to use the plainest of plain language. It is assumed that the reader is familiar with the tenets of Pragmatism, Operationalism or Functionalism. If not, he may refer to innumerable philosophical works, or, if he must glance and run, he must perforce accept the fact that those terms are here used interchangeably to remind the reader of our basic idea that ideas are hypotheses.

Charles Sanders Peirce, who contributed the term pragmatism to the language of philosophy, insisted always that the term was intended to designate a method. Pragmatism, he warned, is not a Weltanschauung, nor a doctrine of metaphysics, nor even an “attempt to determine any truth of things.” It is simply a method of ascertaining meanings, of making them clear, and of pointing a way for the successful determination of the truth of things. Peirce's practice consistently belied his preaching in this regard, for his exposition of the method involved a metaphysical system of considerable scope; and this, it seems to me, was unavoidable. Yet it was as a method that Peirce first presented his distinctive point of view, and it is primarily as a method that I wish to consider it here. Into metaphysics, or Weltanschauung, we shall surely be led; despite Peirce's pronouncement, I make no apology for that.

For some time there have been appearing in the philosophical literature hints and suggestions that the so-called “problem of the external world” should be abandoned, not primarily because it is of little pragmatic significance, but rather because there is really no such problem to be solved. The publication of Reichenbach's Experience and Prediction has now stimulated a resurgence of these suggestions. In the course of his discussion of the book in the April Philosophy of Science Professor Ernest Nagel has taken occasion to argue briefly that this problem, which Reichenbach attempts to solve, cannot even be stated unless one assumes its solution. And in a similar vein more recently Dr. William Barrett has also criticized Reichenbach and has then gone on to present certain fundamental logical considerations which, it is alleged, guarantee that the expression “Is there an external world?” cannot designate a legitimate philosophical problem. The situation, as he describes it, is as follows. The sentence “There is an external world” or the equivalent sentence “There is a physical object” can be confirmed in a physicalistic language only if one assumes the existence of certain physical objects. This procedure is of course circular. These sentences cannot therefore be confirmed, and, since the verifiability theory of meaning is accepted, the questions derived by transferring them into the interrogative mood cannot be meaningfully asked. A similar result is asserted to follow if one employs a perception language for science in place of a physicalistic language, since there is a parallelism between these two languages such that for every expression in the one there will be a corresponding expression in the other.

Strange as it may seem, the traditional principle of causality is based on two contradictory assumptions, both of which are generally accepted, explicitly or implicitly, by the contemporary physicists as well as philosophers. That they are not always willing to acknowledge this paradoxical fact, does not save them from the perplexing situation. The two assumptions, in brief, are:

(1) That nothing can act at a distance or across an interval of time, without something mediating between the bodies or events; and

(2) That every cause precedes its effect and may be located at a distance from it.

At the end of the last century, there began a movement away from traditional philosophy and towards a closer contact of philosophical thought with empirical science. Philosophers following this course were met halfway by groups of scientists, mostly physicists and mathematicians, who in their own field had found themselves face to face with problems which traditionally belonged to philosophy. But since neither of these two groups was inclined to respect conventional boundaries, they joined forces and the result of their endeavors proved challenging to both philosophy and science. Various aspects and representative theses of this movement are known to-day as logical positivism, operationism, physicalism or scientific empiricism. For the movement as a whole, however, the term logical positivism is now becoming generally used. The present paper should be considered as a selective and partly historical survey of the methodological discussion in psychology from the standpoint of logical positivism.

The philosophy of science embraces the metaphysical, epistemological and methodological problems which arise in the study of the special sciences and perhaps no branch of the philosophy of science is more deserving of careful investigation than the borderline discipline between philosophy and scientific psychology. The philosophical problems resulting from the impact of psychology upon philosophy include such traditional problems as the existence, nature and origin of consciousness, the relation of the conscious to the unconscious and subconscious mind, the nature and continuity of the self, and the relation of consciousness to its neural conditions. All these problems originate in empirical psychology and are soluble, if at all, only by appeal to psychological evidence and thus through the cooperative efforts of the philosopher and the psychologist. Unfortunately the gulf between philosophers and psychologists is as wide if not wider than that which exists between philosophers and other groups of scientists. The chief obstacle to a philosophical psychology is the alienation of psychology from philosophy which followed the attainment by psychology of its status as an independent science. Psychology as a young and vigorous science, revolting against the parental restraint of philosophy, utterly repudiated philosophy and philosophical modes of thought and, at the same time, philosophy on its side breathed a sigh of relief to be rid of a difficult and recalcitrant offspring. Thus psychological science became more hostile to philosophy than her elder sister sciences, and philosophy went its own speculative way in utter disregard of scientific psychology. Indeed “Psychologismus” has become among philosophers a term of such severe reproach that to refute a philosophical position in certain quarters one need only demonstrate that it is psychological in its origin and foundation. Thus the revolt of psychology against philosophy, natural and inevitable though it was, has been so violent and prolonged as to be detrimental to both psychology and philosophy alike.

It is frequently supposed that there exist propositions of a kind appropriately designatable as “self-contradictory”; and in this paper I propose to examine this supposition. It may first be pointed out that some philosophers use the word “proposition” in such a sense that to say there exist self-contradictory propositions is unquestionably to say what is true. They give it such a usage (which they claim to be its only significant one) as to make it synonymous with “declarative sentence”; so that a self-contradictory proposition would be a sentence of the general form s · ~s, and the supposition (a) that there are self-contradictory propositions would be equivalent merely to the supposition (b) that there are sentences of the form s · ~s. In this sense of “proposition” it seems quite plain that there are self-contradictory propositions. But it is not this usage of “proposition” with which I shall be concerned in this paper; rather, my concern will be with the usage given it, whether significantly or not, by philosophers like Mr. Russell, who hold that propositions are what literally significant declarative sentences stand for, or express.

The Unity of Science movement is directed primarily toward the further advancement of science, but a second phase is entered when the assessment of its significance for various aspects of civilization is undertaken. In this second phase would fall investigations of the utility of its resources in relation to educational problems.