esis of the movement represented by Bergson. The new realism,
though it manifested itself in a great variety of forms, was in all
its various guises definitely intellectualistic. This was shown by
the general dissatisfaction of its representatives with the Kantian
strain in the thought of their older contemporaries. What is
particularly objected to, as the source of " idealistic" or "men-
talistic " fallacies, is the Kantian view that both sense, in virtue
of the pure forms of intuition, and thought, in virtue of its
scheme of categories, are in part constitutive of the objects they
apprehend. The tendency common to all the writers who may
be classed together as typical of the latest forms of realism is to
regard both sense and thought as simply apprehensive of data
which do not depend on the percipient mind, either for their
existence or for their apprehended qualities and relations.
The degree of consistency with which this doctrine is held varies
with its individual representatives, but, thought out consistently,
it plainly tends in the direction of ultra-intellectualism, since it
leads to the view that the specific task of philosophy is simply
to apprehend as completely as possible objects and relations
which exist and have the characters which they are discovered by
science to have quite independently of the perceiving or knowing
mind. On the psychological side this tendency shows itself in its
extreme form in the doctrine that known relations between ob-
jects are purely non-mental, not the " work of the mind," as
T. H. Green had taught. The function of the intellect is not to
create relations between its objects, but simply to discover what
the relations between them are. On this point there seemed to be
general agreement between such writers as Alexander, Russell,
and Moore in England, Woodbridge, Fullerton, Montague and
others in America, and Couturat in France. It is a natural devel-
opment of the same view that the attempt should be made to
deny the existence of what are commonly called " presentations,"
and to hold that in sense perception we have only two distinguish-
able factors, an extra-mental presented thing and the process of
apprehending it. Presentations, i.e. mental " contents," which
psychologists have usually regarded as immediate objects of
cognition from which we may go on to infer propositions about
the extra-mental things which are their exciting causes, are then
dismissed as unnecessary fictions. This is the point of view
adopted by Prof. Alexander, according to whom there are,
strictly speaking, neither contents of cognition nor cognitive
states or processes. The contents of the mind consist solely
of conations of various types, and the universe is thus reduced
to conative tendencies and the objects in which they terminate
and find their satisfaction.
This extreme view, that presentations had no existence, was not shared by all the writers who exhibited the realistic tendency. Thus, in his Problems of Philosophy (1911), Mr. Bertrand Russell maintains that apart from the general predicates of things and the relations between them, which are universal and must not be said to exist, what we know is composed of minds, physical things and sense-data, i.e. what are more usually spoken of as sense-qualities: red, sweet, salt, and the like. Sense-data are neither mental (processes of consciousness) nor physical. We are acquainted directly with our own minds and also with sense- data. But we have no acquaintance either with physical things or with minds other than our own. Any knowledge we have of the minds of others or of physical things is merely knowledge by description, and its possibility depends on the truth that things with which we have no acquaintance can be indirectly known if it is possible to describe them in terms of sense-data with which we have acquaintance. Since Mr. Russell accepts the familiar arguments against the physical reality of sensible qualities, it follows on his theory that we have no acquaintance with physical things. I know a physical thing only by inference, as, e.g., " the cause of such-and-such a definite group of sense-data." This is a description obtained by a combination of sense-data which I know at first hand by acquaintance with the universals " the " and " cause of," and with these universals I have also immediate acquaintance. My acquaintance with the meaning of " the " secures that the otherwise unknown physical thing signified by the descriptive phrase shall be strictly individual.
Thus my knowledge through sense-data of physical objects is like the knowledge I have, e.g. about the "magnates of the Education Department," when I know that there is such a body, and what it does, but have never met any of its members. For science, the most important point in the theory of knowledge is that we can be directly acquainted with relations and universals, though these entities do not properly exist. Immediate knowl- edge of this kind is what we mean by a priori knowledge, i.e. knowledge which does not involve awareness of any proposition about what actually exists. As the principles of inference are among the relations with which we have acquaintance a priori, we are able to have a derivative a priori knowledge of all truths which are deduced by correct inference from a priori principles with which we are directly acquainted. This covers the whole domain of the sciences of logic and pure mathematics, as, con- trary to the Kantian opinion, all pure mathematics can be shown to consist of propositions deduced logically from premises which involve only logical concepts and relations with which we are directly acquainted. It is added that we must also include under a priori knowledge our direct acquaintance with the relative intrinsic worth of various goods. This is why there can be a science of ethics. The chief special work of the particular type of realism represented by Mr. Russell and his associates was done, in close connection with the earlier work of mathematicians like Peano and Frege, in the field of mathematical logic, with a view to the exhibition of pure mathematics as a vast body of deduc- tions from the principles of the logic of relations, first treated with due elaboration in the third volume of E. Schroder's Algebra der Logik (1895), and applied with particular thorough- ness to arithmetic in Frege's Grundgesetze der Arithmetik (1893- 1903). The magnum opus of Messrs. Whitehead and Russell, Principia Malhematica, represents the fullest development of logic as a calculus of relations. The most brilliant account of the principles and methods of the mathematical logicians is, per- haps, that of Couturat (Principes des Mathemaliques, 1905).
Russell and also G. E. Moore made some application of their doctrine to ethics (see G. E. Moore, Principia Ethica, 1903; Ethics, 1912; and Russell, Philosophical Essays, 1910), but with- out any very satisfactory results. From their point of view the principal business of ethics is to discover true propositions about the relative intrinsic worth of different " goods." As both writers assume that there are a plurality of such propositions, and that each of them is known a priori independently of the others, the impression they leave upon a reader not previously committed to their theory is that they have really no better standard for determining the worth of various goods than their own personal preferences. It is characteristic of both writers that they assume without serious inquiry that conduct can only be good in a deriva- tive sense as leading to the production of some good other than itself. Hence, though both reject the older forms of utilitarian- ism as ascribing a fictitious worth to pleasure, their own doctrine is itself utilitarian in its general character. Beyond discovering true propositions concerning the relative worth of goods, ethics seeks to furnish rules of right conduct, i.e. conduct which pro- duces good results, but these rules are always of the most rough- and-ready sort and constantly require modification to suit special cases. Hence the ground is left open in practice for an enormous development of reflective casuistry. Messrs. Moore and Russell have furnished us with some acute observations on the relative goodness of various objects, but because of their refusal to look at human life as a whole they cannot be said to have advanced the study of ethics as an interpretation of life. In their ethical writings, slender as they are in bulk, one cannot see the wood for the trees; they are too much occupied with the search for true propositions about " goods " to develop a satisfactory theory of " the good."
Besides the irrationalism of Bergson and the atomistic in- tellectualism of the new realists, one may mention as character- istic of the years preceding the World War a third tendency, which held in some respects a middle place between the former two. This was the revival of philosophical Theism, in connection with which important work was done, especially by Prof. James
