364 INDUCTION. 



and especially of Reid, the causes with which I concern myself 

 are not efficient, but physical causes. They are causes in 

 that sense alone, in which one physical fact is said to he the 

 cause of another. Of the efficient causes of phenomena, or 

 whether any such causes exist at all, I am not called upon 

 to give an opinion. The notion of causation is deemed, by 

 the schools of metaphysics most in vogue at the present 

 moment, to imply a mysterious and most powerful tie, such 

 as cannot, or at least does not, exist between any physical 

 fact and that other physical fact on which it is invariably 

 consequent, and which is popularly termed its cause : and 

 thence is deduced the supposed necessity of ascending higher, 

 into the essences and inherent constitution of things, to find 

 the true cause, the cause which is not only followed by, but 

 actually produces, the effect No such necessity exists for 

 the purposes of the present inquiry, nor will any such doctrine 

 be found in the following pages. The only notion of a cause, 

 which the theory of induction requires, is such a notion as 

 can be gained from experience. The Law of Causation, the 

 recognition of which is the main pillar of inductive science, is 

 but the familiar truth, that invariability of succession is found 

 by observation to obtain between every fact in nature and 

 some other fact which has preceded it; independently of all 

 consideration respecting the ultimate mode of production of 

 phenomena, and of every other question regarding the nature 

 of " Things in themselves." 



Between the phenomena, then, which exist at any instant, 

 and the phenomena which exist at the succeeding instant, 

 there is an invariable order of succession; and, as we said 

 in speaking of the general uniformity of the course of nature, 

 this web is composed of separate fibres ; this collective order 

 is made up of particular sequences, obtaining invariably 

 among the separate parts. To certain facts, certain facts 

 always do, and, as we believe, will continue to, succeed. The 

 invariable antecedent is termed the cause ; the invariable con- 

 sequent, the effect. And the universality of the law of causa- 

 tion consists in this, that every consequent is connected in 

 this manner with some particular antecedent, or set of ante- 



