As Art is intuition, so Philosophy is the pure concept: it is easy to see that all the formal definitions of Philosophy that have ever been given, as science of the first principles, of the ultimate causes, of the origins of things, of norms, of values, of categories, are mere verbal variants of the pure concept. Even the most materialistic and realistic philosophies, since matter itself or nature or reality are assumed by them as principles of universal validity, as concepts or ideas, fall within the limits of this definition. In this sense there is no philosophy which is not idealistic: the differences between one philosophy and another are nothing but differences in the elaboration of the pure concept. What follows from this identification cation of philosophy with the pure concept is that all philosophies are, of necessity, systematic, inasmuch as it is impossible to think the pure concept as a singular or particular one, outside its relations with the whole. This systematic character belongs to every philosophical proposition, and not only to the actual systems of philosophy: the solution of every particular philosophical problem implies a vision of that problem in its universality, that is, in the system. We are constantly reminded of this exigency by the fact that a new and original elaboration of particular problems does actually react on the whole of our thought; and that we are often compelled to revise our fundamental opinions by the discovery of a difficulty which at first presents itself in one sphere of thought only.
Of such a process, the whole of Croce's philosophy is a continuous exemplification, but nowhere so clearly apparent as in the progress of his conception of history. His first step had been that of reducing history to the general concept of art, thereby emphasizing the concreteness and individuality of history, as opposed to the abstractness of the natural sciences, the concepts of which, in that early stage, he could not yet distinguish from those of philosophy. In the Estetica the conception is still practically the same, history resulting from the intersection of art and philosophy through the application of the predicate of existence to the intuitive material. In his first Lineamenti di Logica, history appears as the ultimate product of the theoretical spirit, "the sea to which the river of art flowed, swollen by the waters of the river of philosophy." But in the same Lineamenti he had not yet arrived at the identification of the definition and the individual judgment, which in his second Logica constitutes the final form of the pure concept, Croce's original interpretation of Kant's a priori synthesis. Between the first and the second Logica, Croce wrote his Filosofia della pratica, in which he denied the duality of intention and action, as in the Estetica he had denied the duality of intuition and expression: an intention which was not also an action appeared to him, as we shall see, inconceivable. It was by analogy with his treatment of this duality, that he solved the duality between the concept (in the sense of definition) and the individual judgment, which was also a duality of philosophy as antecedent and history as consequent, as he perceived that a concept which is not at the same time a judgment of the particular is as unreal as an intention which is not at the same time an action.
These are the successive steps by which Croce reached his doctrine of the identity of history and philosophy, one of the most discussed and of the least understood among his theories. We shall come back to it later. But a few more hints on its meaning can already be given here. It is clear that by introducing the predicate of existence as essential to history Croce had already abandoned the conception of history as pure, that is, non-logical, non-intellectualized intuition: but the predicate of existence is insufficient to form a judgment, without the addition of the other predicates, that is, of the whole concept. The predicate of existence can only tell us that something exists, but not what it is, that exists: the determination of the singular, in its relations with the particular and the universal, is implicit in the historical judgment, even when it is not openly enunciated. Such judgments as: This thing is, or has been, seem to present the proper form of the historical judgment; no other predicates than that of existence are here visible, but my talking of this thing implies that I know what this thing is; the other predicates are concealed in the subject. Every historical statement is, therefore, a perfect individual judgment. Its concrete and individual character, which Croce had asserted in his early theory, is here maintained by the presence of the subject, though the subject itself, in history, is seen not in its intuitive purity, as in poetry, but as a concrete determination of the concept. The identification of philosophy and history is not so much the effect of a more intellectualized view of the historical processes, as of the progressive consciousness acquired by Croce of the inherent concreteness and individuality of the universal—of that realistic view of the concept as expressed by his elaboration of the logical a priori synthesis.
The old distinction between a subjective and an objective treatment of history receives a new light from the foregoing considerations. It is impossible to make history without judgment, and, therefore, history is in a sense irreducibly subjective. But the subjectivity of history is not the arbitrary and capricious subjectivity of the individual historian, who introduces his own passions and tendencies into the historical narrative: it is the subjectivity of thought, of the earnest and dispassionate research of truth, which coincides with the only conceivable objectivity. What we call objective truth is not reached by renouncing thought, but only by making our thought deeper and truer. The historian who permeates with his thought his recreation of the past (and if he did not, he would be recreating the past as poetry, and imagination, not as history) needs not add a judgment of value to his statements of fact: the identity of value and fact presents itself once more to us in the intrinsic structure of the historical judgment. Whatever the aspect of reality to which we turn our attention, true history and true criticism coincide.
A consequence of this identification of history and philosophy is that the only legitimate divisions of history are those that correspond to the distinctions of the concept,—history of knowledge and of action, of art, of thought, of the practical activity of man; and that the relation among the different branches of history is similar to that of the distinctions of the concept within the concept itself: that is, the history of one particular form of human activity is nothing but the history of the whole spirit of man as it realizes itself under one of its aspects, a statement that we have already illustrated when speaking of the history of art and poetry. Other divisions of history are possible and useful, deduced from empirical concepts (such as the state, the church, the drama, the novel, society, religion, etc.), but they are divisions of practical convenience, mnemonic and didascalie expedients, and not rigorous distinctions. Empirical concepts are, in fact, in constant use in history, but as instruments, not as constituents of historical thought. History is of the individual sub specie universalis, and not of the practical generalizations. This peculiar function of the empirical concept in history marks the distinction between history and the natural sciences, the final irreducibility of history to sociology.
As history is reduced to philosophy through the identification of the historical with the individual judgment, so philosophy is reduced to history through the identification of the definition with the individual judgment. Since every philosophical proposition is an answer to a given question, and every question or problem is individually and historically determined, the whole course of the history of philosophy is in constant function of the general course of history. This is the truth contained in Hegel's formula of the identity of philosophy and history of philosophy, which had been revived in Italy, when Croce was meditating on these problems, by his friend Gentile: a formula which he finally accepted and transformed into that of the identity of history and philosophy, in accordance with his view of philosophy as a moment or grade of the spirit of man. The a priori synthesis which constitutes the reality both of the definition and of the individual judgment is, at the same time, the reality of both philosophy and history. The distinction between the two is a purely didactic one: in the first the emphasis is laid on the definition and the system, in the second on the individual judgment and the narrative. But because the narrative includes the concept, every narrative clarifies and solves philosophical problems, and, on the other hand, every system of concepts throws light on the facts which are present to the mind. The confirmation of the soundness of the system is in the power it displays to interpret and narrate history; the touchstone of philosophy is history. The concept, in affirming itself, conquers the whole of reality, which becomes one with it.
We shall deal more briefly with Croce's treatment of the organization of the empirical and abstract concepts in the natural and mathematical sciences because his views coincide in their general lines with the economic theory of science, which is the view of scientific method elaborated by the scientists themselves in the last decades, and differ from it only in so far as they are comprehended in a vaster system of thought. Croce's polemic against pseudo-scientific philosophy, which was amply justified at the beginning of his career, has now lost a good deal of its actuality, since the ambitious attempts to organize the concepts of science into a system of ultimate truth have finally collapsed under the blows inflicted on their authors by science itself, and are now relegated into a few academic and journalistic backwaters. On the other hand, there is no doubt that his discussion of scientific methods, though sufficient for his purposes, is far from being as exhaustive as his discussion of either art or philosophy.
The natural sciences are systems of empirical concepts, that is, of practical elaborations of knowledge, and, therefore, they do not belong to the sphere of theoretical, but to that of practical activity. This proposition must not be understood as referring to the practical ends, or applications, of science: action requires a knowledge of the individual fact with which we are to deal, and, therefore, the true antecedent of action is not science, but an individual (or historical) judgment. The natural sciences are not subservient to action, but they are actions in the service of knowledge. Because of the empirical and pragmatic character of their concepts, it is impossible either to unify them in a single concept, or to divide them according to rigorous distinctions. The natural laws which they evolve are the same empirical concepts, which give rise to the creation of classes and types, expressed in a different form; their empirical character is confirmed by what Boutroux called their contingency, which is nothing but the reflex of their arbitrary formation. Even the most general of those laws, that of the constancy and uniformity of nature, assumed as the foundation of so much pseudo-scientific thought in the nineteenth century, is a mere postulate of practical opportunity, without which it would be hardly possible to construct any science: it is the first economic principle of scientific method, not an attribute of objective reality.
The truth of the natural sciences, that truth of which they and their empirical concepts are an abbreviated transcription, is the historical datum, the knowledge of actual individual happenings. History is the hot and fluid mass which the naturalist solidifies in the schematic moulds of classes and types. The naturalistic discoverer is, therefore, an historical discoverer and the revolutions of the natural sciences are steps in the progress of historical knowledge. The difference in method between history and the natural sciences is not due to the supposed difference between a higher and a lower reality (spirit and nature), or to the fact that nature has no history; nature is perpetual activity and change, that is, history, as much as the spirit, but the progress of nature is less clearly perceptible and less interesting to us than that of the human reality, and, therefore, an abbreviated transcription is more apt to satisfy our needs in relation to the knowledge of what we call nature than to that of the spirit. The nature that has no history, and which is opposed in dualistic systems of philosophy to the spirit of man, is not the actual, historical reality of nature, but the empirical concepts of the natural sciences, their classes, types and laws, conceived as an objective reality and substituted for that reality. In this sense, nature is not a special object, but only a method of treatment, as is proved by the fact that that same method, applied to the so-called higher and spiritual reality, by such sciences as psychology, sociology, or comparative philology, creates the same kind of naturalistic categories in the domain of the spirit. It is of nature in this sense that the idealist denies the real existence, since the time when Bishop Berkeley repudiated matter as a mere abstraction. And here again, the scientist comes to the support of the idealist with his keen awareness of the pragmatic character of his hypotheses on the ultimate physical constituents of reality.
It is through this theory of the natural sciences that Croce succeeded in eliminating naturalistic transcendence from his thought, and, singularly enough, his first impulse in this direction came to him from his æsthetic studies, through his criticism of literary genres, of grammars, of the particular arts and of rhetorical forms. He saw how through them "nature" introduces itself, as a construction of the human spirit, in the pure spiritual world of art; and having denied its reality in art, he proceeded to discover it everywhere not as reality, but as an product of abstracting processes. This must not be interpreted as meaning that the naturalistic method is an illegitimate hybrid: it has its uses in its proper place, and not less in the study of mind than in the study of nature. It is only by mistaking its constructions or fictions for realities, that we can be tempted to deduce from the natural sciences a philosophy of nature, or from the applications of the naturalistic method to art and to the history of man, an æsthetics or a philosophy of history. But the natural sciences themselves are not responsible for the errors of philosophical naturalism. That such errors should not be limited exclusively to philosophers, but very often appear within the body of sciences like biology or psychology or sociology, is easily explained by the fact that no scientist is a pure scientist: but poor philosophy does not become science simply because it finds place in scientific books. The quarrel between vitalists and mechanicists, for one instance, is a philosophical (or historical), not a scientific dispute: and it reveals itself, ultimately, as the opposition not of conceivable realities, but merely of different methods in the elaboration of the historical datum. The coherent and clear-minded biologist is to-day a mechanicist, not because mechanism is the essence of reality, but because it is the postulate of his research. The vitalist, on the other hand, is inevitably brought by the trend of his thought to abandon science and to become more or less deliberately a philosopher. It is enough to mention in this connection such names as Driesch or Bergson.