The principle of insufficient reason is one of those philosophic concepts that are highly symptomatic concerning the ultimate presuppositions of the person who accepts them as fundamental. This principle asserts that where we do not have sufficient reason to regard one possible case as more probable than another, we may treat them as equally probable. It has been violently rejected by various logicians, asserted to produce absurdities, and yet has remained persuasively attractive, being accepted, for example, by such an outstanding logician as Dotterer. It may hence be worth while to inquire what the acceptance of this principle implies and what is the source of its persuasiveness.

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.

Biology is in a unique position among the natural sciences. It is not simply complex physics and chemistry, for living organisms have a psychological as well as a physical side. Even as physical systems their character is highly special, largely because their material substance is continually changing; perhaps it was from them that Heraclitus derived his idea that all is flow. The comparison with vortexes and candle flames is an old one. Wilhelm Ostwald included living organisms in his class of “stationary systems”: they represent not a static but a kinetic equilibrium, what we now often call a “steady state”; there is a balance of constitutive and dissipative processes. Materials and energy converge to the living center, undergo there characteristic transformations, among which complex chemical and structural syntheses are conspicuous, and are again distributed at random to the surroundings. The living organism is thus the seat of a special type of physical and chemical activity found nowhere else in nature, and it is significant that this is associated with psychical activity—demonstrably in the higher organisms, by implication in the lower.

Many centuries ago, at the very beginning of the systematic development of philosophy, Plato declared that the thinker's domain comprises “the wholeness of things;” and indeed, the earlier thinkers took all knowledge for their province and did not hesitate to discuss problems now referred to art, psychology, economics, mathematics, or physics. Since then the meaning of philosophy has appreciably changed, however, and the intellectual descendants of the great founder of the Academy no longer claim the monopoly of all fields of study. For there appeared in the meantime a mighty competitor—or should we say a partner?—in the pursuit of truth, namely, science.

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.

The term coherence is used in many connections. We often speak of coherent reasoning, coherent activities, coherent bodies, and coherent phenomena. In science this term is often used to indicate continuity of a structure in space and time. If many individuals can simultaneously observe similar sets of coherent phenomena, we infer with some justification, first, that the phenomena observed have some kind of correspondence with activities in an external world, that is, a world independent of the existence of the individual observers, and second, that the coherence itself is an attribute of the external world. In a recently published article, to which I shall make several references in this paper, I have called attention to the fact that the science of physics is based on the form and the changes in form of an immediately observed phenomenological world, called the physical world, which can be completely characterized as a structure in space and time. In his analysis of the foundations of the science of physics Eddington has clearly shown that theoretical physics deals exclusively with structures of the type described in the mathematical theory of groups, and that our knowledge of the physical world could have been reached by our sense of vision alone. Coherence in the physical world is that characteristic of the structure which describes the more or less permanent relationship between phenomena in different parts of space at approximately the same time, or a regular sequence in the changing phenomena at approximately the same region of space.

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.

This paper is a study in restraint on freedom of speculation. In view of the subtlety of the subject it has seemed advisable to begin the report with a list of the presuppositions initiating and determining the study. These are as follows:

1). That freedom of speculation is a prerequisite to sound mental health, in individuals as well as in large-scale social units.

2). That, consequently, individual and institutional faculties are alike deficient if and insofar as they prevent or abridge such freedom.

3). That the same factors operating in one aspect to restrain the influence of promulgated theories operate in another aspect to inhibit the free conception and hamper the expression of speculation not so promulgated.

4). That as it is the purpose of individual philosophizing to surround with coherent speculation or theory subjects of primarily individual interest, it is the purpose of institutional philosophizing similarly to invest with theory subjects of common social interest.

5). That speculation in general, whether individual or institutional, is free when the prevalent tendency is for subjects of comparable interest to be accorded comparable quantities of speculation; and that when and insofar as this tendency does not prevail speculation is to that extent not free but restrained.

In this paper certain basic assumptions about causation will be made explicit and then an attempt will be made to show, on the basis of those assumptions, that causation must be supplemented by an extra-causal operation of a selective nature. It is hoped that our assumptions will have in their own right a certain general acceptability, but since assumptions or “postulate sets”, whether antecedently acceptable or not are usually chosen for the purpose of proving something already deemed desirable, a word should be said as to why it was thought desirable to argue for selectivity.

Two different aspects of knowledge are frequently distinguished by the logician and philosopher: the non-repetitive and the repetitive. However, this distinction is imperfectly supported by careful observation, since no two objects or events are known to be exactly alike, and no two objects or events are completely different. In spite of this relativisitic state of affairs, there is some value in distinguishing between the thinker or student who is primarily interested in the unique, peculiar and non-repetitive phenomena of experience and the person whose emphasis is on general, repetitive and predictable observations. The approaches and mental operations of these two classes of agents are essentially different, although the world they experience may be the same. The first concentrates on one item at a time, the result being a restriction of his attention away from other objects or events of the same class. The generalizing student usually controls his mental operations fully as much, but in this case attention to the unique is held in abeyance and comparisons are deliberately fostered. The essential difference thus becomes a matter of the rejection of the comparative method of procedure by the first and overwhelming dependence on that method on the part of the generalizer.

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 statements traditionally labelled “necessary,” among them the valid theorems of mathematics and logic, are identified as “those whose truth is independent of experience.” The “truth” of a necessary statement has to be independent of the truth or falsity of experiential statements; a necessary statement can be neither confirmed nor refuted by empirical tests.

The admission of genuinely necessary statements presents the empiricist with a troublesome problem. For an empiricist may be defined, in terms of the current idiom, as one who adheres to some version, however “weak,” of a principle of verifiability. One, that is, who claims that no statement can have cognitive meaning unless its truth depends, however indirectly, upon the truth of experiential statements; unless it can be provisionally confirrned or refuted by empirical tests. Allowing that some necessary statements have cognitive meaning, then, would be to provide a prima facie case against the validity of the principle of verifiability.

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.

As presented by some, operationalism in sociology is Kantian in its view of the universe, of the assumptions and limitations of science, and of the scientist's ability to analyse and present the reality of the universe.

In his exposition, George A. Lundberg rests operationalism upon a twofold basis. First there is a materially-conceived nature. This is expressed in the terms “X,” “the cosmos,” or “that which arouses certain responses.” We do not know, cannot know, nor can science tell us, anything about the nature of this X, save that it precipitates responses. This position is qualified by making existence always relative to some responding organism. There is nothing final in the terms “existence” or “reality,” such as is usually implied in the terms “truth” and “fact.” An objective reality existing entirely independently of anyone's observations is believed by Lundberg to be incompatible with his philosophical basis. The only justification for this position is “… its demonstrable efficiency in helping us comprehend our world.”

“Reason,” said Lao Tze some twenty five hundred years ago, “is of all things the emptiest. Yet its use is inexhaustible.” With equal justice, he might have said the same of language. But Lao Tze, whose profound metaphysical probing appeared to carry him beyond the reach of linguistic aid, was led to insist that “Those who know do not speak; those who speak do not know.” Yet the “Old Philosopher,” as he is known to the Chinese, might be said to admit, by the very implications of his insistence, that language can exercise the greatest influence on thought, if only, in his viewpoint, to nullify it. Today we acknowledge this influence by reversing the great metaphysician's statement, those without speech (i.e. language) in some form or other cannot know.

The R-Being is, by definition, that entity which possesses all qualities which, expressed in English adjectives, begin with the letter R. It is of course unknown, at the commencement of our inquiry, whether any such entity exists, but it is nevertheless possible to determine the characteristics which such a being, whether existent or not, must possess.

Doubts concerning the validity of logic are as old as the empirical criticism of science. In the last two decades the idea that truth is relative to given sets of basic assumptions has been prominent; and the controversy about the principle of excluded middle has focussed renewed attention upon the nature of logic and its fundamental principles.

Recent investigations in formal logic have contributed greatly to the understanding of the principles of logic. It is simply a misunderstanding to conclude from them that the logical principles have been suspended, despite the various formal structures which are called “logics.” The purely formal treatment of problems concerning the foundations of logic, while necessarily undertaken as far as it can go, has essential limitations.

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.

The word ‘social’ is used in many different contexts, in each of which the word has a general root meaning, common to all contexts in which it is found. But in addition, there are other specific meanings, peculiar to each context, which are intended by the user of the term. Frequently, these other meanings of the term are not made explicit, and hence ambiguities arise.

The root meaning of the term involves some sort of relationship among two or more people. ‘Social’ is derived from the Latin socius, meaning ‘companion’. At least two people are involved here: 1) the person having the companion, and 2) the companion. Nothing is intended as to the nature of the relationship between the two or more people. In each context in which the term ‘social’ is used it has this root meaning. This paper is concerned, however, with those other aspects of the meanings of the term which are intended to specify more precisely the nature of this relationship among two or more people, and therefore are different in different contexts. The contexts will be isolated, and the more specific meanings of the term in these different contexts will be distinguished and made explicit.

Most of man's organs can be utilized in more than one way. His hands can be used to grip and to push, his throat can serve to swallow and to expel, he uses his tongue to taste and to talk, his nose to breathe and to smell.

If each mode of activity required the use of a different organ, a man would have to be much more cumbersome than he now is, or he would have to give up doing some of the things of which he is now capable. He would need at least a score of hands if he needed one with which to grasp, another with which to lift, a third with which to push, a fourth with which to twist etc. Because he has only two, capable of doing twenty different things, he is much more compact and flexible than he otherwise would be.