196 Professor Nichol [Feb. 16, 



my own, it is an Idoluni specus. When those spectres are laid the 

 way is clear for unbiassed investigation. 



Having got all the facts that are, about the object of my research, 

 I have next to range them under three Tables : (1) of Affirmatives 

 containing a collection of all the known instances that agree in 

 having the same quality, e.g. to take Bacon's example, of all bodies 

 that give forth heat. (2) of Negatives, a collection of examples of 

 bodies otherwise similar (else the list would be endless) which do not 

 agree in the same nature, i.e. which do not give out heat. A main use 

 of this table is to discover the nature sought by observing qualities 

 absent in the analogous nature. Thus boiling water is hot, ice is cold, 

 living bodies are hot, dead bodies are cold ; but in boiling water and 

 in living bodies there is motion of parts, in ice and dead bodies they 

 are fixed. Does it not seem, therefore, that motion of parts is of the 

 nature of heat ? The stress Bacon lays on Negative Instances is the 

 first clear assertion of the principle " Audiatur et altera pars " in 

 Philosophy, and he uses it quaintly of superstitions, in the question, 

 "Where are the tablets hung of those that perished with their vows ? 

 The employment of this table along with the first corresponds to the 

 " Joint Method of Agreement and Difference " in modern Logic. (3) 

 While the use of the third, that of Majus and Minus, more or less 

 intensity of the quality, is Mill's " Method of concomitant Variations." 



So far all is plain. The use of these Tables is in the main modern 

 Induction. There is wanting only the recognition of Theory, of 

 Hypotheses as a motive and principle of arrangement ; nor is Bacon 

 without a vague idea of the value of shrewd conjecture, which he 

 expresses under the name of Vindemiatio Prima or Permissio Intel- 

 lects, i.e. an indulgence to the understanding to gather early grapes. 



Meanwhile he throws into his Table of Exclusions everything about 

 Heat which is not present in the affirmatives, present in the negative, 

 everything which increases when the phenomenon decreases and vice 

 versa. The conclusion drawn from this as regards Heat, not so far 

 astray as critics, to whom detail is everything, have assumed, is yet 

 partly a guess. Bacon had worked up to the modern canon of Residues, 

 but he failed properly to apply it, for of his Prerogative Instances, 

 meant as severer tests, he has only given " a few illustrations." He 

 was hurried away by the very impatience, misled by the same love of 

 uniformity which in his predecessors he had denounced. Above all 

 he had set before himself an impracticable design. He thought he 

 could put labels on the whole of Nature. He did not know by how 

 many parts her subtilty passes the subtilty of the human mind, or 

 how many new instruments were needed to wring her secrets from 

 her tenacious grasp ; and his lists are often a jumble of things great 

 and small ; his instances and conclusions, medleys of shrewd sug- 

 gestion and almost childish fancies. Like Galileo, he maintained 

 that Nature must be interpreted like a book, that we must learn the 

 alphabet — though far longer than he knew — before arranging the 

 facts of an Historia Naturalis, but the Induction which would have 



