First Principles	313
we are concerned, this is much the same thing. To assume an
unknowable substratum as the source from which all things
proceed or are evolved is equivalent to assuming that they
come up out of nothing ; for that which does not exist for us
is for us nothing ; that which we do not know does not exist
qua us, and therefore it does not exist. When I say " we," I
mean mankind generally, for things may exist qua one man and
not qua another. And when I say " nothing " I postulate
something of which we have no experience.
And yet we cannot say that a thing does not exist till it is
known to exist. The planet Neptune existed though, qua us,
it did not exist before Adams and Leverrier discovered it, and
we cannot hold that its continued non-existence to my laun-
dress and her husband makes it any the less an entity. We
cannot say that it did not exist at all till it was discovered, that
it exists only partially and vaguely to most of us, that to many
it still does not exist at all, that there are few to whom it even
exists in any force or fullness and none who can realise more
than the broad facts of its existence. Neptune has been dis-
turbing the orbits of the planets nearest to him for more
centuries than we can reckon, and whether or not he is
known to have been doing so has nothing to do with the
matter. If A is robbed, he is robbed, whether he knows it
or not.
In one sense, then, we cannot say that the planet Neptune
did not exist till he was discovered, but in another we can and
ought to do so. De non appareniibus et non existentibus eadem
est ratio; as long, therefore, as Neptune did not appear he
did not exist qua us. The only way out of it is through the
contradiction in terms of maintaining that a thing exists and
does not exist at one and the same time. So A may be both
robbed, and not robbed.
We consider, therefore, that things have assumed their
present shape by course of evolution from a something which,
qua us, is a nothing, from a potential something but not an
actual, from an actual nothing but a potential not-nothing,
from a nothing which might become a something to us with any
modification on our parts but which, till such modification has
arisen, does not exist in relation to us, though very con-
ceivably doing so in relation to other entities. But this Pro-
tean nothing, capable of appearing as something, is not the