128 INTRODUCTION 



degree. One reality pervades them all ; no one of them 

 is separated from another by any impassable barrier. 

 Body is confused soul ; soul is clear and distinct body. 

 Self-consciousness is not a unique certainty or reality, 

 but a high degree of clearness and distinctness in that 

 which is already real in lower forms. The self may be 

 exclusive, self- limited, individual ; but it is so only in 

 common with every other substance. There is no sub- 

 stance which is not potentially an Ego, a self-conscious 

 being. What Descartes and Locke both ignore is the 

 internal movement, the becoming, the growth_ and 

 development, which is of the essence of every substance. 

 For them a thing, a mind, an idea, a principle is what 

 it is, unchangeably; so that either, as in the case of 

 Descartes, the variety of real thought is contained, perfect 

 and entire, within its unity, and is to be set forth by pure 

 sub-sumption, the lifting out of class from within class, or, 

 as in the case of Locke, the unity of real thought is a mere 

 aggregate of its varieties, the elements remaining un- 

 changeable into whatever groups we may gather them. 



As against Descartes, Leibniz denies th-e complete Separation 



of Matter and Mind. 



Accordingly, Leibniz brings against Descartes's view of 

 mind essentially the same argument as he used against 

 Descartes's view of matter. The Cartesian view of sub- 

 stance as that which is in itself and is conceived through 

 itself, without need of anything else, resulted in the 

 complete separation of matter and mind. Leibniz, on 

 the other hand, unifies without absolutely identifying 

 them, through his view of substance as that which is 

 continually in process of perceiving or representing all 

 things. Thus, against Descartes's view of matter as an 

 independent substance, Leibniz argues that a true 

 doctrine of substance makes matter by itself an abstrac- 

 tion, for it is really the confused perception which is 

 potentially clear and distinct perception, apperception or 



