Though this doctrine may appear unfamiliar to the logician, yet we all constantly depend on it in our analysis of error. We know that error is due to the passions or interests of men, which cloud the intellect, and the more an error is foreign to our own ways of thinking, the easier it is for us to discover the practical motives which help us to explain it away. That category of errors which goes under the name of national prejudices, for instance, is transparent in its origins to every man belonging to a nation other than the one in which a particular set of such prejudices is commonly accepted. And other categories of errors, social, professional, religious, and so on, are of the same kind, affecting only certain classes of men, because of the passions or interests or traditions which belong to them by reason of their peculiar practical associations. In the field of politics, or in any kind of heated discussion, this research of the practical motive is even pushed to the extreme, and the bad faith of the adversary becomes an obvious axiom. In such cases, the same passions being active on both sides, the research of the practical motive is evidently not pure and disinterested, but is itself moved by a practical motive, and therefore likely to produce a new error, rather than a clear judgment. Therefore, though rigorously speaking there is no difference between the error which is a deliberate lie and that which is due to a more or less justifiable weakness, and there is no error which is not in bad faith, which is not due to a deliberate act of will, yet, from an empirical standpoint we may distinguish between errors in bad and in good faith, and recommend tolerance and indulgence for the latter kind. But tolerance is not indifference. Croce went so far, in drawing the consequences of his doctrine, as to justify the Holy Inquisition; and in fact all our modern advocates of religious and political tolerance have really shaken our faith in its methods, but not in its principle, which is that of the moral responsibility of error. The Holy Inquisition moreover was bound to clash with the freedom, which is not the freedom of error but the freedom of truth, because it placed its faith in a static, extrahuman truth, as against the veritas filia temporis, the truth which is engendered and conditioned by history, by the peculiar problems and intellectual climate of the age, and which is the object of our modern faith; and therefore defeated its own end by striking at the roots of the value for the upholding of which it had been established.

Passing from the problem of the nature of error to that of the forms actually assumed by philosophic error, Croce accepts Vico's definition of error, as an improper combination of ideas, and therefore defines such forms, by deducing the number of possible improper combinations from his own conception of the legitimate forms of theoretical activity. This phenomenology of error is one of the main tasks of logic, while the refutation of particular philosophical errors is the task of philosophy as a whole. We shall rapidly survey these general forms, in which it will be easy for the reader to recognize the logical (or illogical) structure of many particular errors criticised in the preceding chapters.

The pure concept can be improperly combined with, or exchanged for, the pure intuition (art), or the empirical and abstract concept (the natural and mathematical sciences); or it can be improperly split in its unity of intuition and concept (a priori synthesis), and arbitrarily put together again, either as a concept which simulates an intuition or as an intuition which simulates a concept. Hence the five fundamental forms of error: æstheticism, empiricism, mathematicism, philosophism, and historicism or mythologism. To these must be added other forms originated from combinations of the preceding ones: dualism, scepticism, and mysticism.

We have dealt elsewhere with both æstheticism and empiricism. Of the first, the most recent form is that which pretends to build a philosophy of pure intuition or of pure experience, that is, of an experience which, not being touched by any intellectual category, is also pure intuition. Empiricism is practically all the current philosophy of our times, from the positivism of Comte and Spencer to the more modern types of the so-called philosophic elaboration of scientific knowledge. Mathematicism is a rarer and more aristocratic form of error: it does not consist in the application of the mathematical method to the exposition of philosophical concepts, which is a mere didactic expedient, more or less convenient, but insufficient to characterize the quality of the concepts themselves; its true exponents are those philosophers or mathematicians who take mathematical fictions, such as the dimensions of space, for realities, and proceed to speculate on such a foundation. The near future seems to promise a great extension of this kind of philosophy, through the prevailing interest in the theory of relativity, which is fondly supposed to contain the germs of a revolution in thought. Both empiricism and mathematicism lead to a dualistic conception of reality, by opposing either the facts of scientific and historical knowledge, that is, a collection of facts limited in space and time, to an infinite reality beyond that knowledge, or our actual world of space and time, to worlds, spaces and times mathematically conceivable, but of which we have no experience. The passage from this dualism to spiritualism and other kinds of superstition, which in our times seem to be so closely associated with certain forms of pseudo-scientific thought, is of the easiest. The naturalistic experiments by which we attempt to peer into the mystery of the so-called unknown or unknowable, hoping to detect the spirit itself as matter, however subtle or light, and such theories as that of the identity of the spiritual world with the four-dimensional space, are evidences of this immediate connection between superstition and science, for which, obviously, not science is responsible, and not ignorance even, but a chain of more or less deliberate errors in each case reducible to definite practical motives. From the point of view of the ethics of intellect, there is no difference between the frank impostor who is moved to speculate on other people's feelings only by greed, and the scientist who makes his science minister to his own private feelings, and is hardly, if at all, conscious of his fraud.

Of the other two forms of philosophic error, philosophism, consisting in the abuse of the purely logical element, and therefore in an usurpation on the part of philosophy against either history or science, tending to the formation of a philosophy of history and of a philosophy of nature, is less common now than in times of more active and original speculation. The most conspicuous examples are to be met with among Germany's classical thinkers; and we have already hinted at the connection between one particular logical error, the undue extension of the dialectic process to the distinctions of the concept, and to the empirical concept, which is the basis of Hegel's philosophies of history and nature. Both these sciences attempt an a priori deduction of the individual and of the empirical, a process which is in itself absurd and contradictory. They duplicate history and science with a series of concepts, which, unless they are the same which constitute history and science (in which case we have history and we have science, and not a philosophy of history or of nature), are necessarily empty of any concrete determinations. But though Croce points to philosophy of history and philosophy of nature as to the two typical instances of philosophism, yet he is ready to acknowledge that a good deal of thought that has gone under those names in the past has had a large influence in moulding many of our historical and philosophical conceptions, and, in the case of the second one, in helping us to realize the unity and spirituality of nature, and to recognize in the history of nature the same principles operating in the history of man. Croce's idealism, in fact, does not divide nature from the spirit except in the logical sense which has been made clear in the preceding chapter; it does not relegate nature in an unknowable sphere beyond the reach of human minds. It unifies spirit and nature, but a parte subjecti, and not a parte objecti, and reduces nature to the spirit, rather than the spirit to nature; which is the only process that makes such a unification intelligible and significant.

The last of the five fundamental forms of philosophic error consists in the arbitrary separation of the subject from its predicate, of history from philosophy, and in the consequent position of the subject as predicate, that is, of a mere representation as a concept. This may sound rather abstruse, but can immediately be made clear by adding that what Croce has in mind in this definition is the production of myths. This error he therefore calls either historicism (from the logical process by which it is produced), or mythologism (from the form which it commonly assumes). A myth is to him not a mere poetic or æsthetic imagination, but necessarily includes an affirmation or logical judgment. It differs also from allegory, in which the relation established between a poetic fiction and a concept is always more or less openly declared to be arbitrary, and the two terms are not confused with each other. In a myth, on the contrary, the poetic fiction assumes the actual function of the concept, transforming both philosophy and history into a fable or legend. Errors of this class are frequent in every system of philosophy, when the thinker, either consciously and deliberately, as in the case of Plato, or unwittingly, as in Kant's Ding an sich or in Schopenhauer's Will, fills the gaps of his real speculation with a mere image. But mythologism is more generally the form of religious error, since there is no religion without a logical affirmation embodied in a myth. If myth and religion coincide, as the distinction between myth and philosophy is that of error and truth, of a false and a true philosophy, we must conclude that religion as truth is one with philosophy, or, as Croce expresses it, that the true religion is philosophy; and this appears to Croce to be the conclusion of all ancient and modern thought in regard to the history of religions. Philosophies have sprung up in all times from the soil of religious thought, and more or less completely resolved in themselves, and logically clarified, the obscure substance of myth. This is Croce's clear-cut, unequivocal solution of the problem of the relations between philosophy and religion: there is no place reserved anywhere in his system for an either internal or external revelation other than that perpetual revelation of truth, which is at the same time history and philosophy.

From the possible combinations of these five fundamental forms of error, three more complex ones are derived: dualism, when two contradictory methods, one logically legitimate and the other illegitimate, or both equally false, are brought together, and considered to be both philosophically valid; scepticism, when the mind, in the presence of confusion and error, asserts the mystery of reality, which is the problem itself, but denies its own power to deal with it; and finally, mysticism, when even that last semblance of thought, by which the sceptic affirms that there is a mystery, is abandoned, and the immediate actuality of life is regarded to be the only truth. Dualism leads inevitably to the conception of a double reality, and we have already seen how the whole of Croce's speculation continually tends towards the logical unification of dualities, as with spirit and nature, value and fact. Every philosophical problem seems to present itself to his mind as involved in a dualistic difficulty; every solution becomes satisfactory to him only when the last shreds of dualism are eliminated from it. While scepticism is a logical error (the affirmation of a purely negative position), it contains within itself one of the essential moments of every progress in thought, the scepsis, or philosophical doubt, which is the negation of an error, and therefore the germ of every true affirmation. As for mysticism, we have dealt with it elsewhere as being one of the untenable aspects of logical scepticism; we may add that, if it ever obeyed the laws of internal coherence, we should not even be able to discuss it, since its only conceivable expression would be an ecstatic silence.

The same character of necessity that invests these forms of the logical error is present also in the false solutions of other philosophical problems, and we need only refer the reader to our discussion of æsthetic theories. In both cases, not only the number, but also the logical succession, of the necessary forms of error, depends on the number of possible arbitrary combinations of the spiritual forms, or concepts of reality. But infinite, on the other hand, are the individual forms of error, as infinite are the individual forms of truth: the problems are always historically conditioned and variable, and so are also the solutions and the false solutions, determined by feelings, passions, and interests.

From error to truth, there is no gradual ascent. The passage is described by Croce as a kind of spiritual conversion: the erring spirit, fleeing from the light, must convert itself in a researching spirit, eager for light; pride must yield to humility; the narrow love for one's abstract individuality, widen and lift itself to an austere love, to an utter devotion to that which is above the individual, becoming Bruno's eroico furore, Spinoza's amor Dei intellectualis. In this act of love and enthusiasm, the spirit becomes pure thought and attains the truth, or, rather, transforms itself into truth. And the possession of truth is at the same time possession of its contrary, of error transformed into truth; to possess a concept is to possess it in the fulness of its relations, and therefore to possess, in the same act, all the ways in which that concept, for instance, of the æsthetic activity, is at the same time the concept of hedonism, intellectualism, empiricism, and so on. The two kinds of knowledge, that of truth and of its contrary, are inseparable: the concept is at the same time affirmation and negation.

From this absolute possession of truth, we may distinguish a stage of research, which is not yet thought, but only the operation of the practical will creating certain conditions for thought. Seen in the light of this process, the series of errors through which a mind goes, when guided by a will to gather its materials and prepare itself to think, transforms itself into a series of attempts or hypotheses. An error is an error when there is a will to err; the hypothesis, however, into which the error is transmuted by the new will is not yet truth, and becomes truth only in the act of its verification; but it is no longer an error, because it does not affirm itself as truth, but only as a means or help for the conquest of truth.