ONE:"I'm not going away till I've got them," he said doggedly.Disjunction is, in truth, the primordial form of all reasoning, out of which the other forms are successively evolved; and, as such, it is common to man with the lower animals. You are taking a walk in the country with your dog. You come to a stream and jump over it. On measuring the distance with his eye, the animal is afraid to follow you. After waiting a little, he first runs up stream in search of a crossing, and, finding none, returns to look for one in the opposite direction. Failing there also, he comes back once more, and either ventures on the leap or makes his way home by some other route. Now, on considering the matter a little more382 closely, we shall find that hypothetical reasoning takes its rise from the examination of each separate alternative presented by a disjunctive premise. A plurality of courses being open to us, we consider what will ensue on the acceptance or rejection of each. The dog in our illustration thinks (after a canine fashion) that if he jumps he may fall in; if he does not, he will be left behind. Hector will not take refuge within the walls, because, if he does, Polydamas will triumph over him; nor will he offer terms of peace, because, if he does, Achilles will refuse them. Once more, categorical reasoning is developed out of hypothetical reasoning by the necessity of deducing consequences from a general rule. Hector must have argued from the known characters of Polydamas and Achilles, that in certain circumstances they would act after a certain manner. We may add, that this progress of conscious reasoning is a reproduction of the unconscious logic according to which life itself is evolved. All sorts of combinations are spontaneously produced, which, in consequence of the struggle for existence, cannot all survive. Those adapted to the conditions of life are selected, on trial, at the expense of the rest; and their adaptation or non-adaptation is determined in accordance with categorical laws. Furthermore, the framing of a disjunctive proposition necessitates the systematic distribution of possibilities under mutually exclusive heads, thus involving the logical processes of definition, division, and classification. Dialectic, as Plato understood it, consisted almost entirely in the joint performance of these operations;a process which Aristotle regards as the immediate but very imperfect precursor of his own syllogistic method.276 You cannot, he says, prove anything by dividing, for instance, all living things into the two classes, mortal and immortal; unless, indeed, you assume the very point under discussionto which class a particular species belongs. Yet this is how he constantly reasons himself; and even demonstrative reason383ing, as he interprets it, implies the possession of a ready-made classification. For, according to him, it consists exclusively of propositions which predicate some essential attribute of a thingin other words, some attribute already included in the definition of the subject; and a continuous series of such definitions can only be given by a fixed classification of things.
THREE:Nor leave unburied and exposed to sight
THREE:It was natural that one who ranged with such consummate mastery over the whole world of apparent reality, should believe in no other reality; that for him truth should only319 mean the systematisation of sense and language, of opinion, and of thought. The visible order of nature was present to his imagination in such precise determination and fulness of detail that it resisted any attempt he might have made to conceive it under a different form. Each of his conclusions was supported by analogies from every other department of enquiry, because he carried the peculiar limitations of his thinking faculty with him wherever he turned, and unconsciously accommodated every subject to the framework which they imposed. The clearness of his ideas necessitated the use of sharply-drawn distinctions, which prevented the free play of generalisation and fruitful interchange of principles between the different sciences. And we shall have occasion to show hereafter, that, when he attempted to combine rival theories, it was done by placing them in juxtaposition rather than by mutual interpenetration. Again, with his vivid perceptions, it was impossible for him to believe in the justification of any method claiming to supersede, or even to supplement, their authority. Hence he was hardly less opposed to the atomism of Democritus than to the scepticism of Protagoras or the idealism of Plato. Hence, also, his dislike for all explanations which assumed that there were hidden processes at work below the surface of things, even taking surface in its most literal sense. Thus, in discussing the question why the sea is salt, he will not accept the theory that rivers dissolve out the salt from the strata through which they pass, and carry it down to the sea, because river-water tastes fresh; and propounds in its stead the utterly false hypothesis of a dry saline evaporation from the earths surface, which he supposes to be swept seawards by the wind.205 Even in his own especial province of natural history the same tendency leads him astray. He asserts that the spider throws off its web from the surface of its body like a skin, instead of evolving it from within, as Democritus had taught.206 The same thinker had320 endeavoured to prove by analogical reasoning that the invertebrate animals must have viscera, and that only their extreme minuteness prevents us from perceiving them; a view which his successor will not admit.207 In fact, wherever the line between the visible and the invisible is crossed, Aristotles powers are suddenly paralysed, as if by enchantment.