196 INTRODUCTION 



is taken by the conception of mechanism, through which 

 we describe the relations in which things are for thought. 

 Such relations as those between the phenomena of the 

 soul and the phenomena of the body can be described on 

 purely mechanical principles : that is to say, the condi- 

 tions of their connexion can be stated as laws. And the 

 theory of a pre-established harmony is not required (not 

 to say that it is insufficient) to explain how the phenomena 

 of the soul have any connexion with those of the body 

 how, for instance, physical nerve-motion passes into 

 psychical sensation. It is impossible for our thought to 

 explain this ; but it is just as impossible for our thought 

 to explain how one physical phenomenon is invariably 

 connected with another physical phenomenon how, for 

 instance, the burning match is connected with the explod- 

 ing gunpowder 1 . In neither case can thought do more 

 than describe a connexion invariable in our experience. 

 Science must be content with a ( practical occasionalism ' 

 as distinct from the ' theoretical ' (i. e. absolute ontological) 

 ; occasionalism ' of the Cartesians 2 . 



Thus in Lotze we find the principles of the philosophy 

 of Leibniz modified by Kantian influences. Like Leibniz, 

 Lotze in his application of the principles of contradiction 

 and of sufficient reason keeps them sharply apart from 



a pre-established harmony not, indeed, explain anything, but 

 tolerably well describe the facts. ... It is only if individual things 

 do not float independent or left to themselves in a vacuum across 

 which no connexion can reach only if all of them, being finite 

 individuals, are at the same time only parts of one single infinite 

 substance, which embraces them all and cherishes them all within 

 . itself, that their reciprocal action, or what we call such, is possible.' 

 Microcosmus, bk. ix. ch. i, 5 (Eng. Tr., vol. ii. pp. 597, 598). 

 Cf. Metaphysic, bk. i. ch. 5, 63 sqq. (Eng. Tr., vol. i. p. 150). 



1 ' As in our life we see the physical motions of external nature 

 employed as stimuli to excite that in ourselves which is far 

 higher conscious sensation : so, we think, throughout the universe 

 mechanical events are but the external tissue of regularly crossing 

 stimuli, designed to kindle at innumerable points, within in- 

 numerable beings, the true action of a more intelligent life.' 

 Microcosmus, bk. iii. Conclusion. (Eng. Tr., vol. i. p. 399.) 



2 Streitschrift, p. 96. 



