the validity of the principle, others attempted to restrict it." Among other arguments, it was alleged, by the advocates of the former opinion, if the principle be admitted, that everything must have a sufficient reason why it is, rather than why it is not,-on this hypothesis, error itself will have such a reason, and, therefore, must cease forthwith to be error. Many philosophers, as Wolf and Baumgarten, endeavoured to demonstrate this principle by the principle of Contradiction; while others, with better success, showed that all such demonstrations were illogical." In the more recent systems of philosophy, the universality and necessity of the axiom of Reason has, with other logical laws, been controverted and rejected by speculators on the absolute. a As Feuerlin and Darjes. See Bachmann, Logik, p. 56, Leipsig, 1828; Cf. Degerando, Hist. Comp. des Syst. de Phil., t. ii. p. 145, ed. 1804.-ED. B See Bachmann, Logik, p. 56. With the foregoing history of the laws of Thought compare the same author, Logik, § 18-31.-ED. y [Kiesewetter, Allgemeine Logik, P. i. p. 57]; compare Lectures on [On principle of Double Nega- LECT. V. LECTURE VI. STOICHEIOLOGY. SECTION 1.-NOETIC. tion. VI. THE FUNDAMENTAL LAWS OF THOUGHT-THEIR LECT. HAVING concluded the Introductory Questions, we entered, in our last Lecture, upon our science itself. Recapitula The first part of Pure Logic is the Doctrine of Elements, or that which considers the conditions of mere or possible thinking. These elements are of two kinds, -they are either the fundamental laws of thought as regulating its necessary products, or they are the products themselves as regulated by those laws. The fundamental laws are four in number, the law of Identity, the law of Contradiction, the law of Excluded Middle, the law of Reason and Consequent." The products of thought are three,-1°, Concepts or Notions; 2°, Judgments; and 3°, Reasonings. In our last Lecture, we considered the first of these two parts of the doctrine of elements, and I went through the general explanation of the contents and import of the four laws, and their history. Without recapitulating what was then stated, I shall now proceed to certain general observations, which may be suggested in relation to the four laws. a See, however, above, p. 86, note a.-ED. in VI. And, first of all, I may remark, that they naturally LECT fall into two classes. The first of these classes consists of the three principles of Identity, Contradiction, General and Excluded Middle; the second comprehends the to the four principle of Reason and Consequent alone. This clas- fundamen sification is founded both on the different reciprocal thoughtl connection of the laws, and on the different nature of into two their results. tal laws of These fall classes. sification con- This clas once founded, 1°, proxi- ference of On the dif connection The between the laws them In the first place, in regard to the difference of nection between the laws themselves, it is at evident that the first three stand in a far more mate relation to each other than to the fourth. first three are, indeed, so intimately connected, that selves. though it has not even been attempted to carry them up into a higher principle, and though the various and contradictory endeavours that have been made to elevate one or other into an antecedent, and to degrade others into consequents, have only shown, by their failure, the impossibility of reducing the three to one; still so intimate is their connection, that each in fact supposes the others. They are like the three sides of a triangle; not the same, not reducible to unity, each pretending with equal right to a prior consideration, and each, if considered first, giving in its own existence the existence of the other two. This intimacy of relation does not subsist between the principle of Reason and Consequent and the three other laws; they do not, in the same necessary manner, suggest each other in thought. The explanation of this is found in the different nature of their results; and this is the second subject of our consideration." In the second place, then, the distinction of the four a For a later development of the Author's philosophy as regards the VOL. I. distinction here indicated, see Dis- G VI. difference which the severally accomplish. LECT. laws into two classes is not only warranted by the difference of their mutual dependence in thought, but, 2. On the likewise, by the difference of the end which the two of the end classes severally accomplish. For the first three laws two classes not only stand apart by themselves, (forming, as it were, a single principle viewed in three different aspects,) but they necessitate a result very different, both in kind and in degree, from that determined by the law of Reason and Consequent. The difference in their result consists in this,-Whatever violates the laws, whether of Identity, of Contradiction, or of Excluded Middle, we feel to be absolutely impossible, not only in thought but in existence. Thus we cannot attribute even to Omnipotence the power of making a thing different from itself, of making a thing at once to be and not to be, of making a thing neither to be nor not to be. These three laws thus determine to us the sphere of possibility and of impossibility; and this not merely in thought but in reality, not only logically but metaphysically. Very different is the result of the law of Reason and Consequent. This principle merely excludes from the sphere of positive thought what we cannot comprehend; for whatever we comprehend, that through which we comprehend it is its reason. What, therefore, violates the law of Reason and Consequent merely, in virtue of this law becomes a logical zero; that is, we are compelled to think it as unthinkable, but not to think it, though actually non-existent subjectively or in thought, as therefore necessarily non-existent objectively or in reality. And why, it may be asked, does the law of Reason and Consequent not equally determine the sphere of general possibility, as the laws of Identity, Contradiction, and Excluded Middle? Why are we α VI. opinions the limits to view the unthinkable in the one case not to be LECT. equally impossible in reality, as the unthinkable in the other? Some philosophers have, on the one hand, Two counter asserted to the Deity the power of reconciling contra- regarding dictions; while, on the other, a greater number have of objective made the conceivable in human thought the gauge of possibility. the possible in existence. What warrants us, it may be asked, to condemn these opposite procedures as equally unphilosophical? In answer to this, though the matter belongs more properly to Metaphysic than to Logic, I may say a few words, which, however, I am aware, cannot, by many of you, be as yet adequately understood. tive spheres To deny the universal application of the first three The respeclaws, is, in fact, to subvert the reality of thought; of the two and as this subversion is itself an act of thought, it the laws of in fact annihilates itself. classes of thought defined and illustrated. application three laws the reality When, for example, I say that A is, and then say to deny the that A is not, by the second assertion I sublate or take universal away what, by the first assertion, I posited or laid of the first down; thought, in the one case, undoing by negation what, in the other, it had by affirmation done. But of thought. when it is asserted, that A existing and A non-existing are at once true, what does this imply? It implies that negation and affirmation correspond to nothing out of the mind,—that there is no agreement, no disagreement between thought and its objects; and this is tantamount to saying that truth and falsehood are merely empty sounds. For if we only think by affirmation and negation, and if these are only as they are exclusive of each other, it follows, that unless existence and non-existence be opposed objectively in the same manner as affirmation and negation are a Compare Le Clerc, Logica, part ii. c. 3.-ED. |