which it treats of correspond to the forms of existence, they are conditioned by the objective reality. They stand in essential relation not only to the content of knowledge in general, but also to the particular nature of the content in the modifications they take for the time being.

Logic has both a metaphysical and an anthropological side, inasmuch as it is founded upon the universal laws of existence, and also upon the laws of the life of the mind. These two elements, however, do not make independent parts of logic, but only serve for the foundation of the regulative laws. They are consequently, in the treatment of individual portions of the part concerned, to be borrowed from Psychology and Metaphysics as auxiliary axioms, or to be explained only in so far as this is necessary for the purpose of Logic. Logic does not directly treat of Being, Essence, Causality, the moving cause, the final cause, &c., nor yet of the principles of Psychology, any more than does Dietetic the chemical and physiological processes; but it can refer to such investigations as preparatory or following. At the same time, such investigations as those regarding the possibility of knowing things, regarding the validity of our notions of Space, Time, Causality, &c., are not to be excluded from Logic,' for these investigations have to do with our knowledge, not with the forms of existence as such.

The relation of subject and predicate in the categorical judgment to the forms of existence, subsistence and inherence, or the relation of superordinate and subordinate notions to the way in which things exist in genera and species-may provisionally serve to give a clearer idea of the connection between logical and metaphysical or ontological forms. Cf. § 8. Many writers wrongly interpret the expression Formal Logic,' as if it necessarily involved the abstraction of every

1 As Drobisch thinks, Log. 3rd ed. pref. p. xvii.

2 E. g. Steinthal, Gram. Log. and Psych. (Berlin, 1855), p. 146.

relation to the actual. Logic is formal because it is the doctrine of the correct form or way of thinking, even if this form is conditioned by the endeavour after an agreement of the contents of thought with actual existence. It is Subjectively-formal Logic which directs its attention exclusively to the subjective agreement of thinking with itself.

Kant and his school have connected the distinction of formal Logic, in the sense that it exhibits only the laws of analytical knowledge, and the criticism of the pure reason, which inquires into the possibility of a universally valid synthetic knowledge, with the distinction of the analytic and synthetic formation of judgments (§ 83). The Aristotelian Logic is an analytical theory of thinking, but the formal Logic, in the Kantian sense, a theory of analytical thinking.

Beneke's distinction of analytical or logical' thinking from the synthetic elements of thinking, and Ulrici's division of thinking into productive (synthetic) and separative (analytic), are related to Kant's.

It does not seem proper that a distinction, which of course is valuable and true in connection with the formation of judgments, should be raised to be the principle of a division of the whole of Logic into two separate parts. This procedure would be like a geometer's, who divides his science into two separate divisions, as its propositions could be proved with or without the eleventh axiom of Euklid. Such methods of treatment have their full scientific value as monographs on single axioms, but cannot determine the whole articulation of a system, which must rest on a more comprehensive point of view.

Material

§ 3. The aim of knowledge is TRUTH. Knowledge arrived at the certainty of truth is SCIENCE. (or real) truth must be distinguished from (formal) correctness. Material truth in the absolute sense, or simply truth, is the agreement of the content of knowledge with what actually exists. Material truth in the relative sense, or phenomenal truth, is the

agreement of the mediately acquired content of thought with the immediate outer or inner perceptions which exist when the soundness of the mind and of the bodily organs is undisturbed, or would exist under the corresponding outer conditions. According to some logicians formal truth is the absence of contradiction, or the agreement of thoughts with one another. Material truth includes formal, in the sense of absence of contradiction; but there may be the absence of contradiction without material truth. In the fuller sense of the term, formal truth or correctness is the consistency of the activity of knowledge with its logical laws. When the form of perception, as well as of thinking, meets all the logical demands, then (at least the relative) material truth must exist; and formal correctness in the fuller sense guarantees this. But correctness of thought only warrants that the connection between the antecedents and consequents is known, as it really is, with truth, and that therefore where the antecedents have material truth the consequents have it also. With respect therefore to the aim and end of knowledge, Logic is the scientific solution of the question relating to the criteria of truth; or, the doctrine of the regulative laws, on whose observance rests the realisation of the idea of truth in the theoretical activity of man.

In opposition to truth in the logical sense-the agreement of the thought with its object, and supplementary to it, is the ethical meaning of the word—the correspondence of the object with its idea or inner determination. The explanation of the so-called 'formal truth,' as 'the harmony of knowledge with itself in complete abstraction from all objects whatever and

from all their differences, is insufficient." The explanation of the so-called transcendental truth, as the orderly arrangement of real objects, goes as far on the other side: Veritas, quae transscendentalis appellatur et rebus ipsis inesse intelligitur, est ordo eorum, quae enti conveniunt.'2

In so far as Logic seeks to determine whether and how far agreement between the content of knowledge and objective reality is attainable, it is a critique of knowledge. In so far as it teaches the procedure by which the measure of agreement attainable is actually attained, it is Logic in the stricter sense. In the doctrine of perception the one side, and in the doctrine of thought the other side of Logic is the prevalent. Without any inner contradiction, general criteria can be found according to which the agreement of a plan, a picture, a notion, a proposition, &c. with its object can be decided. The reference, what the particular objects are in each case, first comes in the application.

Scepticism and the Critical Philosophy raise weighty objections against the possibility of arriving at and being certain of material truth. In order to be assured of truth in the absolute sense, we must be able to compare our conception with its object. But we never have (says the Critical Philosophy) the object otherwise than in our conception; we never have it pure in itself. We only compare our conceptions with our conceptions, never with the things in themselves. Material truth in the relative sense succumbs to the difficulty which the old Skeptics expressed in the question: Tís Kpivεî Tòv ὑγιεινόν; or τίς ὁ κρινῶν τὸν ὑγιαίνοντα καὶ ὅλως τὸν περὶ ἕκαστα κρινοῦντα ὀρθῶς ?3 Formal validity, lastly, in the sense of absence of contradiction, does not carry us beyond what we, at least implicitly, possess already. How then do we get at the first knowledge, and how can we advance in knowledge? To these general difficulties are to be added particular ones belonging to single forms of knowledge, which will be men1 Kant, Log. ed. by Jäsche, p. 66. 2 Christian Wolff, Ontolog. § 495. 3 Arist. Metaph. iv. 6, p. 1011, A, 5.

tioned afterwards. Their solution is the problem of the whole system of Logic, and cannot therefore be given in this place.' It has been urged against the identification of Logic with the doctrine of the regulative laws of human knowledge, that the principles of Logic would remain were there no things and no knowledge, and that thinking, e.g. a logical inference, can be (formally) correct when it is materially false (because false in the premisses).' But this exception in its first part amounts to a petitio principii. Of course there are certain logical principles in which the relation of thought to things can be got rid of by abstraction. This is true of the law of Identity and Contradiction, which requires the harmony of thoughts with one another (the condition of their agreement with actual existence), as well as of all other laws derived from it. Whoever limits Logic to these portions must maintain that logical principles are valid without reference to objective reality; but he who assigns to Logic a more comprehensive sphere will not admit the correctness of that assertion in its universality. Whoever maintains that Logic does not fulfil its task unless it provides laws for the rigid construction of the scientific notion in its distinction from the mere general conception, for natural division, for the scientific form of Deduction, Induction, and Analogy-whoever does not consider the principle of Logic to be the mere consistency of the thinking subject with itself, but recognises truth to be the agreement with existence, and therefore no mere necessity of thought immanent in the subjective spirit, but rather a correspondence of the logical with the ontological categories, cannot assert that the logical laws, having reference to truth, would be quite as valid if there were neither things nor knowledge. What is brought forward in the second part of the above objection is so

1 Cf. especially § 31, and the tract quoted there on Idealisin, &c. ; also §§ 37, 40-44.

2 Ulrici; cf. Drobisch, Log. 2nd ed. § 7, 3rd ed. § 5, and Pref. p. xviii. According to Drobisch, in his introduction to Logic, only so much is to be taken from the doctrine of knowledge as is needful to get at the data for the peculiar problems.