The nature of universals became an explicit problem for Western philosophy with Socrates. From the Milesians on, the search for a fundamental substance underlying and connecting all phenomena implied the conception; but it was not until Socrates disentangled the question of universality from that of reality in his theory of definitions that it emerged as the traditional problem we know, and one even capable of solution. In so doing, Socrates may be called the founder of a type of inquiry at once abstract and yet specific which we characterize as “phenomenological”. But Plato, coming immediately after him, again muddied the waters by re-introducing the notion of reality in the Ideas before philosophers had a chance to profit by the separation of the two difficulties. In this manner the composite problem was passed on to Aristotle, who, though he differed in his conception of the nature of the reality, nevertheless considered it involved. And from Aristotle the confusion was handed down to posterity, culminating in the deadlock of the theological debates of the Middle Ages.

The question of basic and incorrigible sentences has appeared in connection with certain recent attempts to refine and re-define the meaning of Empiricism. More directly still, the question appears in connection with the problem of verification. It is noteworthy that the question of protocols, more than any other issue, has served to draw out the philosophical differences between the original Wiener Kreis and the Cambridge Analysts. Yet despite their differences both schools are agreed that basic sentences in some sense of the word, are epistemologically necessary.

But if one takes the view, say of the Instrumentalists, that all perceptual knowledge is interpretation based upon accepted theories, and corrected in the light of such theories then basic sentences are quite unnecessary. But among those who employ the term “basic” there is little agreement as to its meaning. The common use of the term has not resulted in a common understanding. And instead of drawing Empiricists together it has succeeded only in driving them apart.

The historical development of a field of human knowledge progresses like the solution of a jig-saw puzzle, the full extent of which is completely unknown. What begins as an ocean may become only a lake; what starts as a grove of trees may develop into a forest. As study advances through the decades, the situation is repeatedly surveyed and the interpretation of the whole is modified to accord with the added information. For these reasons, conceptions and generalizations periodically undergo alteration, as effectively stated and discussed by Cooper (1926). Universal conformity in such conceptions is of course hardly to be expected in matters that deal largely with speculation rather than with simple experimental data.

The problem of induction is to validate inferences from some experiences or data to others. By experiences or data I mean such things as red patches, sounds, tastes, pains. Distinctions between private and public data, between internal and external impressions, between data and objects, are not epistemologically primitive or given but are modes of categorizing the given. The application of categories and the construction of objects are cases of, and so presuppose the validity of, induction.

To hypostatize a construction, or a system of constructions, is in fact to generate what may be called an external world. Examples are physical objects, and scientific objects. And when analysis proceeds, as it often does, by replacing the original subject by constructs, a hierarchy of external systems is generated. Thus, physical objects—e.g., our bodies—are external to data, and scientific objects are external to physical objects.

The infant was first an embryo. Its body is neither new nor untried. Its heart, its liver, lungs and brain, all its nerves and tissues, were in existence some time before, constantly exercised in embryonic ways. The new born infant is an old campaigner on quite familiar terrain.

The embryo begins as a single cell feeding on the food its mother provides. Almost at once it becomes too large, too sluggish and inefficient for its own good, and must either immediately change its tactics and mode of life or be prepared to die. This is an alternative which all growing things face from time to time. The lowest organisms meet the issue by subdividing into a number of similar, smaller, independent cells, each with a life of its own. The embryo meets it by subdividing into a number of different kinds of cells all of which are capable of developing and living according to individual rhythms, but only a few of which are able to exist or develop all alone. Most of the new cells the embryo makes possible must cling to and remain under its sway if they are to continue and prosper at all.

For some while now it has been the fashion to write about Cézanne. Numerous exhibitions of his paintings have been held and a flood of criticism in notices and books has poured forth; yet much remains to be seen and said. The reason for this is that his peculiar approach to art was of the kind which continues to excite interest in the medium itself. We get from him not only an esthetic enjoyment but an imagination stimulated to dwell upon the possibilities of painting. No derogation of other painters, whose more conventional mastery of their craft has been responsible for canvases of great truth and beauty, is implied by the impetus given to the study of esthetics by Cézanne. It simply happens that at the turn of the century a high suggestiveness was imparted to painting at Aix.

The present paper purports partly to reexamine and partly to summarize several points which occupied and still occupy a central position in more recent discussions among empiricist philosophers. As such discussions are essentially attempts at the clarification of terms, it might also be said that this essay intends to contribute to the analysis of certain very general and highly ambiguous expressions. The words in question are, first and mainly, ‘hypothetical’ and, more incidentally or by the way of exposition, ‘atomic', ‘elementaristic', and ‘extensional.’ In general, it is an attempt to show the impact of some of the ideas developed in the work of Carnap; within a prevailingly logical frame of reference in The Logical Syntax of Language and, in a more epistemological setting, in Testability and Meaning. In particular, it wants to eliminate some ambiguities which could arise from an oversimplified reading of certain passages in TM, as for instance: “If by verification is meant definitive and final establishment of truth, then no (synthetic) sentence is ever verifiable” (p. 420). If this passage is understood to assert that every synthetic sentence is hypothetical, then it is either false or several meanings of ‘hypothetical’ are to be distinguished. This distinction, implicit in TM, will upon closer examination prove to be related to the fundamental distinction between statements within and statements about a linguistic structure.

The increase of our knowledge of nature and the multiplicity of phenomena to be studied and investigated has led to specialization in pure and applied science and in practical work. In many instances the individual branches of science became isolated from each other to a considerable degree.

The establishment of the closest ties between the individual lines of knowledge, theoretical as well as practical, is one of the important aims of scientific thought. The analysis of the nature of the factors, used for the quantitative expression of physical processes, shows that many of them have a striking similarity as far as energy is concerned. Such similarity, and even identity, leads one to the conclusion that the concept of energy can serve as the basis for the unified interpretation of physical and, possibly, other phenomena of nature. This paper, which deals with physical processes, is an attempt toward such unification.