seeing altogether, though it must be independent of _our_ seeing. He
is thus led to regard the 'real' table as an idea in the mind of God.
Such an idea has the required permanence and independence of
ourselves, without being--as matter would otherwise be--something
quite unknowable, in the sense that we can only infer it, and can
never be directly and immediately aware of it.

Other philosophers since Berkeley have also held that, although the
table does not depend for its existence upon being seen by me, it does
depend upon being seen (or otherwise apprehended in sensation) by
_some_ mind--not necessarily the mind of God, but more often the whole
collective mind of the universe. This they hold, as Berkeley does,
chiefly because they think there can be nothing real--or at any rate
nothing known to be real except minds and their thoughts and feelings.
We might state the argument by which they support their view in some
such way as this: 'Whatever can be thought of is an idea in the mind
of the person thinking of it; therefore nothing can be thought of
except ideas in minds; therefore anything else is inconceivable, and
what is inconceivable cannot exist.'

Such an argument, in my opinion, is fallacious; and of course those
who advance it do not put it so shortly or so crudely. But whether
valid or not, the argument has been very widely advanced in one form
or another; and very many philosophers, perhaps a majority, have held
that there is nothing real except minds and their ideas. Such
philosophers are called 'idealists'. When they come to explaining
matter, they either say, like Berkeley, that matter is really nothing
but a collection of ideas, or they say, like Leibniz (1646-1716), that
what appears as matter is really a collection of more or less
rudimentary minds.