INDUCTION IN ITS VARIOUS SENSES 47 



proportions of i to 35-5 by weight. They have an innate, inherent, intrinsic 

 tendency to do so, in certain recognized conditions and under the influence of 

 certain known natural agencies. Such is the law of their nature ; for, as St. 

 Thomas profoundly remarks, the law of a being is the natural inclination 

 which carries it towards the end it has to realize in the universe .* 



&quot; Of course, the knowledge of that law does not exhaust all that is know- 

 able about the nature of the bodies in question. By no means. It merely lifts 

 a corner of the veil. The chemical property discovered simply shows us the 

 natures of the bodies that possess it, under one of their aspects.&quot; 



Writers on induction do not usually emphasize the next step, which is the 

 deductive application of the verified law to facts. Yet, if we regard in 

 duction as the total process by which we reach a scientific knowledge of the 

 individual phenomena of nature, this deductive step is essential. The 

 utility of our abstract knowledge of law will always lie in its applicability to 

 concrete facts. &quot; It is a natural property of hydrogen and chlorine to com 

 bine in certain proportions under certain conditions to form hydrochloric acid &quot;. 

 Such is our abstract law. &quot; Here are quantities of those gases in the due 

 proportions ; therefore if submitted to the action of sunlight, they will form 

 a certain quantity of hydrochloric acid with a disengagement of a certain 

 quantity of heat.&quot; Such is our deductive application. It will be seen at 

 once, therefore, how induction contributes to that &quot; knowledge of things by 

 their causes &quot; which is the only knowledge dignified by Aristotle with the title 

 of &quot; scientific &quot;. It will be easy, likewise, to see wherein lies the difference 

 between the method of the rational or deductive sciences and that of the 

 inductive sciences, and what is their point of contact (202). In the former, 

 deduction is immediately possible after the conception of a few definitions or 

 first principles, seen intuitively on a simple analysis and comparison of a few 

 very simple concepts (206). In the latter, on the contrary, deduction from the 

 general law cannot commence until the law . has been established by a process 

 that is often tedious and difficult. 2 



Hence, if we give the name of Induction to that whole method of pro 

 cedure by which we establish the conclusions of the positive sciences, we must 

 distinguish two phases in it (202) : one deductive, which gives us science, in 

 the Aristotelean sense of the word, i.e. the explanation of observed facts by 

 their causes ; the other, preliminary to this explanation, the stage in which 

 the general law is reached, and which alone modern logicians call Induction, 

 in the special and restricted meaning of this term. 3 



Whether this strictly inductive phase of the whole procedure the side by 

 which we ascend from concrete, particular facts to abstract, universal laws 

 involves any reasoning process which is not syllogistic or deductive (192), 

 a comparison of induction with deduction will now enable us to determine. 



1 Stimma Theologica, ia, iae, q. 93, a. 7 sqq. Cf. infra, 217. 



2 &quot;In the former [mathematical], generalization is unnoticed because it is all- 

 pervading; for the relevant conditions are distinguished from the first. In the 

 latter, generalization comes to an end and attracts attention as the result of a long 

 effort ; for all our task is to distinguish the relevant from the irrelevant conditions.&quot; 

 JOSEPH, Logic, p. 509. 



*C/. MELLONE, op. cit., 382-86. 



