210 INTRODUCTION 



one another as regards their nature and incapable of being 

 brought into connexion through their own forces? That 

 would have been to proclaim idealism ; for why should the 

 existence of bodies in general be admitted, if it is possible 

 to regard everything that takes place in the soul as the effect 

 of its own powers, which it would exercise even if it were 

 entirely isolated? The soul and the substratum (entirely 

 unknown to us) of the phenomena which we call bodies are 

 indeed two quite different beings, but these phenomena them- 

 selves, as mere forms of their intuition [Anschammg] depending 

 upon the nature of the subject (the soul), are mere perceptions 

 [Vorstellungen]. Hence the connexion between understanding 

 and sense in the same subject can be understood according 

 to certain a priori laws, as well as the necessary and natural 

 dependence of sense upon external things, without sacrificing 

 external things to idealism. For this harmony between under- 

 standing and sense, in so far as it renders possible a priori the 

 knowledge of universal laws of nature, criticism has given 

 as a reason that without this harmony no experience is pos- 

 sible But we can give no reason why we have just 



such a kind of sense and an understanding of such a nature 

 that through their combination experience is possible ; and 

 further we can find no reason why they, as completely 

 heterogeneous sources of knowledge, always so completely 

 harmonize in rendering possible experiential knowledge in 

 general and more especially (as the Critique of Judgment 

 shows) in rendering possible an experience of nature, under 

 its manifold special and merely empirical laws, regarding 

 which the understanding teaches us nothing a priori. Neither 

 we nor any one else can explain how this harmony is as com- 

 plete as if nature had been arranged expressly to suit our 

 power of comprehension. Leibniz called the principle of this 

 union (especially with reference to the knowledge of bodies 

 and in particular of our own body as a middle term in this 

 relation) a pre-established harmony. Manifestly he did not in 

 this way give an explanation of the union, nor did he profess 

 to explain it. He merely pointed out that we must regard 

 the order established by the supreme cause of ourselves as 

 well as of all things outside of us as involving a certain 

 conformity to end. This purpose is regarded as present at 

 creation (pre-established) ; yet as a pre-established agreement, 

 not between things taken as outside one another, but only 



