s. "To see the material world, or
rather to judge that it exists (since in itself it is invisible), it
is necessary that God should reveal it to us, for we cannot see the
result of his arbitrary will through necessary reason."[21]

But if we know external things only through their idea in God, how do
we know ourselves? Is it also through the idea of us in God? Here we
come upon a point in which Malebranche diverges very far from his
master. We do not, he says, properly _know_ ourselves at all as we
know God or even external objects. We are conscious of ourselves by
inner sense (_sentiment interieur_), and from this we know _that_ we
are, but we do not know _what_ we are. "We know the existence of our
soul more distinctly than of our body, but we have not so perfect a
knowledge of our soul as of our body." This is shown by the fact that
from our idea of body as extended substance, we can at once see what
are its possible modifications. In other words, we only need the idea
of extended substance to see that there is an inexhaustible number of
figures and motions of which it is capable. The whole of geometry is
but a development of what is given already in the conception of
extension. But it is not so with our consciousness of self, which does
not enable us to say prior to actual experience what sensations or
passions are possible to us. We only know what heat, cold, light,
colour, hunger, anger and desire are by feeling them. Our knowledge
extends as far as our experience and no further. Nay, we have good
reason to believe that many of these modifications exist in our soul
only by reason of its accidental association with a body, and that if
it were freed from that body it would be capable of far other and
higher experiences. "We know by feeling that our soul is great, but
perhaps we know almost nothing of what it is in itself." The
informations of sense have, as Descartes taught, only a practical but
no theoretical value; they tell us nothing of the external world, the
real nature of which We know not through touch and taste and sight,
but only through our idea of extended substances; while of the nature
of the soul they do not tell us much more than that it exists and that
it is not material. And in this latter case we have no idea, nothing
better than sense to raise us above its illusions. It is clear from
these statements that by self-consciousness M