136 PART II. SOME IMPORTANT METHODOLOGICAL TERMS. 



This is the rejectio naturarum. Our invalid then proceeds to what 

 is termed by Bacon the Vindemiatio, and pronounces that minced 

 pies do not agree with him." 1 (Ibid., p. 407.) And a little further 

 down he dismisses Bacon in this manner : " His rules are quite 

 proper ; but we do not need them, because they are drawn from 

 our own constant practice." (Ibid., p. 408.) 



If Macaulay's remarkable illustration be typical of the way 

 men reason, Bacon was certainly altogether overrating the value 

 of his efforts, but, in truth, the plain man does not reason in 

 such matters once in a hundred times in accordance with 

 Bacon's precepts. 



Huxley appears to echo Macaulay: "You have all heard it repeated, 

 I daresay, that men of science work by means of induction and deduction, 

 and that by the help of these operations, they, in a sort of sense, wring 

 from nature certain other things which are called natural laws and causes, 

 and that out of these, by some cunning skill of their own, they build up 

 hypotheses and theories. And it is imagined by many that the operations 

 of the common mind can be by no means compared with these processes, 

 and that they have to be acquired by a sort of special apprenticeship to 

 the craft. To hear all these large words you would think that the mind 

 of a man of science must be constituted differently from that of his fellow- 

 men; but if you will not be frightened by terms, you will discover that 

 you are quite wrong, and that all these terrible apparatus are being used 

 by yourselves every day and every hour of your lives. . . . 



"A very trivial circumstance will serve to exemplify this. Suppose 

 you go into a fruiterer's shop, wanting an apple. You take up one, and, 

 on biting it, you find it is sour; you look at it, and see that it is hard 

 and green. You take up another one, and that too is hard, green, and 

 s8ur. The shopman offers you a third; but, before biting it, you examine 

 it, and find that it is hard and green, and you immediately say that you 

 will not have it, as it must be sour, like those that you have already 

 tried. 



"Nothing can be more simple than that, you think; but if you will take 

 the trouble to analyse and trace out into its logical elements what has 

 been done by the mind, you will be greatly surprised. In the first place, 

 you have performed the operation of induction. You found that, in two 

 experiences, hardness and greenness in apples went together with sourness. 

 It was so in the first case, and it was confirmed by the second. True, 

 it is a very small basis, but still it is enough to make an induction from; 

 you generalise the facts, and you expect to find sourness in apples where 

 you get hardness and greenness. You found upon that a general law that 

 all hard and green apples are sour; and that, so far as it goes, is a perfect 

 induction. Well, having got your natural law in this way, when you are 

 offered another apple, which you find is hard and green, you say: 'All 

 hard and green apples are sour; this apple is hard and green, therefore this 

 apple is sour.' That train of reasoning is what logicians call a syllogism, 

 and has all its various parts and terms its major premiss, its minor 

 premiss, and its conclusion. And, by the help of further reasoning, which, 

 if drawn out, would have to be exhibited in two or three other syllogisms, 

 you arrive at your final determination 'I will not have that apple'. So 

 that, you see, you have, in the first place, established a law by induction, 



"Look over the induction, and it will appear that the case is not made 

 out ; an exclusion is wanting : it may have been the mixture of minced pies 

 and brandy which did the mischief." (A. De Morgan, Formal Logic, 1847, 

 p. 218.) De Morgan challenges Macaulay's reasoning throughout. See the 

 above work, pp. 218-224. 



