ing to admit the "possibility of a vacuum and maintain that all space is full, the demonstration is still more simple, for we may ask in what filled space, taken in its entirety, differs from empty space taken in its entirety. Both are infinite; both are ideally divisible and both are really indivisible; both are susceptible of modalities in form or of geometrically defined forms. Perhaps it will be claimed that in full space the particles are movable and can supplant one another; in this case we are back in the preceding line of argument and we shall ask in what these movable particles are distinguished from the immovable particles of space among which they move. Thus the Cartesians, like the atomists, will be obliged to recognize that the plenum is distinguished from the vacuum only by resistance, solidity, motion, activity, in a word, force.
To those who reproach the Leibnizian conception with idealizing matter too much, it may be replied that matter taken in itself is necessarily ideal and super-sensible. Of course it cannot be said that a body is only an assembly of subjective modifications. The Berkeleyan idealism is a superficial idealism, which will not stand examination; for when I shall have reduced the whole universe to a dream of my mind and to an expansion of myself the question will still remain whence comes this my dream and what are the causes which have produced in me so complicated a hallucination; these causes are outside of me and they go beyond me on every side; it would therefore be very inappropriate for me to call them myself, for the I is strictly that of which I have consciousness. The Fichtean Ich, which by reaction against itself thus produces the nicht-ich is only a complicated and artificial circumlocution for saying in a paradoxical form that there is a not-I. At most, we can conjecture with the absolute idealism that the I and the not-I are only two faces of one and the same being, which involves them both in an infinite activity; but we thus reach a position very far from the idealism of Berkeley.
To return to the idealism of Leibniz, I think it can be shown a priori that matter taken in itself is something ideal and super-sensible, at least to those who admit a divine intelligence. For it will readily be granted that God does not know matter by means of the senses; for it is an axiom in metaphysics that God has no senses and consequently cannot have sensations. Thus: God can be neither warm nor cold; he cannot smell the
