We must start with the cosmos as a going concern and proceed at first analytically. Then we can reverse the process and examine the synthesis. Are there any characters which we must attribute to the cosmos taken as a whole—characters which we must take into account in all the various processes of nature? If so, we shall have a framework for metaphysics or cosmology. Owing to our new interest in nature, metaphysics merges into cosmology. In this respect we are going back to the Greeks, whose interest was cosmic.

One of the annoying habits of philosophers is to substitute without warning a normative for a descriptive theory of the topic they are discussing—that is, in what purports to be a statement of how the subject actually presents itself they tell us instead how it ought to present itself. Current treatments of the elusive topic “meaning” seem to me to supply capital instances of this vice. Defenders of a positivist or an operational theory of meaning (I pick these two because of their wide contemporary influence) often give us no hint that their conclusions are conclusions about how the meaning of words ought to be interpreted, not about how, by and large, it is interpreted. Without such a hint their readers naturally suppose that it is the latter problem with which they are concerned, but this is rarely the case; were it so, emphasis could hardly fail to fall on determinants of meaning that are too often neglected by philosophical analysts.

The following definitions and explanations are decisions formulated arbitrarily in a sense. However, the underlying assumptions serving as a guide to their formulation are found in both pragmatism and logical positivism. Yet there has been some confusion of the difference between definitions, axioms, postulates, etc., and as a result there is a confusion of certain phases of formal and factual knowledge. For example, one notices in C. I. Lewis' works that all formal statements are thought of as “definitive.” A more effective word, I believe, is “prescriptive.” Axioms are prescriptive, yet, as will be seen below, they are not definitions, and no one in practice conceives of them as such, as can be seen in mathematical works. Axioms prescribe the logical relationship between two or more concepts or words. If interpreted, the factual referents of the words, whose logical relations have been prescribed in axioms, are different. This is not the case with definitions.

The first aim of science has been analysis. From Leucippus in the fifth century B.C. to Sir Arthur Eddington today, science has tried to reduce nature to simple structural units. For Leucippus the atoms are structurally alike, though they differ in external characteristics, such as size and shape. The aim of physics today is expressed by Sir Arthur Eddington: “The aim of the analysis employed in physics is to resolve the universe into structural units which are precisely alike one another ... so that all variety originates in the structure and not in the elements out of which the structure is built.” To be sure, that is an ideal. In practice we speak of electrons, protons, neutrons. But that does not alter the problem. The question is: Are there such structural units?

Every natural scientist, I should suppose, is an empiricist. But to say this is not to assert that he is consciously such. Very few scientists would presumably consider themselves qualified to state even what is involved in the term, and still fewer would be willing to admit that they are adherents of the position. One might say that natural scientists, in their general outlook, presuppose—in one of the many meanings of this term—the empirical point of view. This probably means that if one could make clear to them what is meant by the term, and if one could convince them that it is proper for scientists to take sides on philosophical issues, they should probably be willing to call themselves empiricists. Expressed otherwise, the general temper and spirit of natural science are those which philosophers tend to identify with the empirical outlook.

Twenty five hundred years ago a Greek named Thales introduced something important into the world. We know little about the details, but there is a persistent tradition going back at least as far as Aristotle that Thales is to be given the credit for being the first person to think in the way that led, without break in continuity, to the development of the scientific method of thought. The conclusions to which Thales came, if we can trust the tradition, are of no value today. The important thing was the way of putting and answering questions. This was carried on by Thales' followers until by the time of Plato and Aristotle the essentials of the scientific method were coming to be recognized even though they were not explicitly and adequately stated in abstraction.

During the past decade or two the influence of theories of language and meaning has made itself felt in almost every field of study, either because, as in the case of psychology and the social sciences, meaning phenomena were part of the subject matter, or because, as in the case of physics and philosophy, the language used in the study demanded analysis and clarification. In recent years there has been (and is being) developed, especially by H. D. Lasswell and his associates, a technique known as content analysis, which attempts to characterize the meanings in a given body of discourse in a systematic and quantitative fashion.

Becoming is interpreted by various sciences. The exact sciences, physics, and chemistry, interpret this universal becoming or change of all things on the model of mathematical equations. In such an equation of quantities or magnitudes, one side always balances the other. We call such a process “circular”. Numbers may be subdivided or contracted, they may change their places or positions, but the sum total of the whole equation remains immutably the same. In this manner mechanics constructs change as a change of positions of unchanging particles in a continuous but divisible space and in a continuous but divisible time. Chemistry constructs qualitative change as a change of unchanging elements in such a fashion that the sum total of the elements involved in such transactions is always completely accounted for. But in the twentieth century becoming entered these closed systems. There are no unchanging atoms now, and no unchanging chemical elements. Both the physical atom and the chemical element, thought immutable before, are now seen to disintegrate, to radiate, to change their character according to their position in the “field” of energy in which they occur.

In one of its numerous meanings “mind” has long represented, and popularly still to some extent does represent, a special non-spatial type of entity transcending and ideally complementing the world of matter. More particularly it has stood for an innate “rational faculty” characterizing men as men; an immaterial substance radically differentiating human beings from animals and by the same token serving to bind them to one another, as brothers are bound by the tie of common blood. Thus conceived, mind traditionally has justified, and so strengthened, the ingenuous a priori regard and appreciation which unlearned persons extend to their fellows for the sole reason that they are human. Upon this conception of mind numerous popular doctrines of “personal dignity,” “human equality”, “individual liberty”, “freedom of conscience”, “inalienable rights”, and so forth, have been rationally grounded. And without it as an inspiration—to name but one dependent consequence—“the American dream”, which Adams describes in The Epic of America, would doubtless never have been dreamt.

This essay has two goals. The first is to define the behavioristic study of natural events and to classify behavior. The second is to stress the importance of the concept of purpose.

Given any object, relatively abstracted from its surroundings for study, the behavioristic approach consists in the examination of the output of the object and of the relations of this output to the input. By output is meant any change produced in the surroundings by the object. By input, conversely, is meant any event external to the object that modifies this object in any manner.

This is a brief sketch of the form which the analysis of the concept of identity would take under the impact of the most recent phase of Scientific Empiricism. The frame of reference is thus that of Carnap's Introduction to Semantics. Most characteristic of this approach is that it reaches its main clarifications by distinguishing between the various connotations of the traditional terms along the three lines of syntax, semantics, and pragmatics. The notion of truth, for instance, must be split into syntactical truth or analyticality, semantical truth, and pragmatical truth. Only the last has something to do with belief and verification. In a somewhat similar manner identity splits, upon closer examination, into three radically different meanings, but it will be seen that the third one has nothing to do with either pure or applied pragmatics. Some of the points I am trying to make have been dealt with, in an interesting manner, in a recent paper by Quine.

Scientists with creative imaginations are ever confronted by two opposing forces. One tempts them to soar into the realm of fancy, and the other cautions them to keep their feet on the ground. These conflicting influences play a significant part in the search for fundamental truth.

The complementary value of philosophical reasoning and matter-of-fact experimentation in the complete fulfillment of science is illustrated by many an epochal discovery. Von Laue had the brilliant thought that the symmetrical distribution of atoms in a crystal presents a lattice sufficiently fine to scatter the exceedingly small waves of X-rays. The idea appeared to be scientifically sound, at least to von Laue, but to certain of his colleagues, classicists all, it was untenable. The kinetic energy or heat-movement of the atoms would, they said, disturb the diffraction phenomena and obscure the picture. Von Laue had confidence in his hypothesis and the courage to see it through, but he also knew that the validity of a scientific theory lies in experimental verification. There were in his laboratory two assistants, both able experimenters, and they proved the truth of von Laue's dream.

The most satisfactory way of isolating the specific issues with which this paper is concerned is by way of a brief summary of the theory and its internal development. The development of the theory embodies two major movements. These are: (a) an analysis of what the author considers the typical perceptual experience, “a perceptual situation”, and (b) the projection of a theory of the physical world on the basis of the results derived. We may consider these in order.

Two essentially different approaches to “truth” should be recognized, although they are not in every respect and on all occasions mutually exclusive. If truth be taken to mean the “most adequate idea (statement, explanation, interpretation, expression) a mind (plural number of minds) is able to perceive at any given time,” the process may, first, be one of immediate intuition, insight or inspiration in which conclusions are arrived at without consciousness of the mediate, detailed steps between recognition of a problem and its solution and without considering all of the possible solutions to the problem; or, it may, second, be one of detailed examination and traversal of the various direct and simple steps to the “truth”, as well as the testing of all other methods of arriving at the same truth. The first method may bring about its result “in a flash”, instantaneously, unpredictably; but the second method is never so rapid, always more laborious, and always consumes more time and energy than the first. That is not to say that the first method always involves less elapsed time between inception and completion than the second; often the first method is marked by delays because the mind in question leaps to other trains of thought before obtaining a solution to the first problem. However, the amount of total time used exclusively to answer the question or solve the problem by the first method is much less than for the second.

The importance of Cassirer's extensive contributions to the philosophical comprehension of mathematics and mathematical physics is generally recognized to be second to none. Nevertheless few indeed in the English speaking world have apparently paid much attention to the penetrating criticisms of Russellian mathematical logic interspersed throughout his works, and formulated in such a way as to bring his own doctrines into that much clearer focus and to render his own position the more convincing.

The last two words of the title for this essay are taken from a paper by R. S. Lillie, and the first phrase is also taken by implication from the same source. The study of chemical phenomena in life has progressed far enough so that underlying chemical causes, involved in Professor Lillie's picture of Biological Causation, may in part be discussed in general terms, and apart from the mass of detail known about the agents and processes involved. Moreover, this mass of detail is now great enough so that even though we are far from having a complete or even a comprehensive picture of these causes at least some of the fundamental principles involved in the chemical aspects of biological causation are clearly revealed.

Epistemology in modern times has been much influenced by the growth of the mathematical theory of probability. The reverse influence is less obvious, but perhaps equally important. This interrelation affords, moreover, an excellent example of the way philosophic ideas, while directing attention in one fruitful line of inquiry, at the same time may inhibit other discoveries until long overdue.

A term and its contradictory exhaust the universe of discourse, but when examined for their relation to each other, I believe they are seen to exhaust that universe in a more particular respect than may have come into notice. They seem to exhaust or annul one of the leading notions of mathematical logic. This notion is the one concerning the whereabouts of the null class.