236 J.J. Haldane
the thought or perception of a cat say, there are two aspects: nature (the con-
ceptual or perceptual content), and the fact of its being actualized in the
thought. An intentional content does not imply the existence of a cognition
in which it is tokened, and so the actual occurrence of a thought calls for an
explanation in terms of some efficient cause of it. Here the anti-realist’s
journey to God may be shorter than that of the realist since it skips out a
chain of interacting natural substances and moves directly to mind as the
cause of ideas, and thence from contingently to necessarily existing mind.
Such is one way in which anti-realism may be linked to theism. This,
however, does not rely on any feature distinctive of anti-realism, but only
on showing that the anti-realist has to allow instances of that from which
the realist argument also starts, i.e. existent being. Next I wish to examine
a different link: one which proceeds from a claim that the realist certainly
denies, namely that the world is constituted by the ways in which we do, or in
which we could, conceive or experience it. The most immediate route to this
anti-realist theses is that laid out by Berkeley in his Treatise Concerning Prin-
ciples of Human Knowledge, when he argues that the common assumption that
the objects we perceive exist independently of their being perceived involves
a contradiction. Berkeley writes:
what are [houses, mountains, rivers] but the things that we perceive by sense,
and what do we perceive besides our own ideas or sensations; and is it not
plainly repugnant that any one of these or any combination of them should
exist unperceived?... all the choir of heaven and furniture of the earth, in a
word all those bodies which compose the mighty frame of the world, have not
any subsistence without a mind, their being is to be perceived or known.^14In reply, the realist will protest that one can think of many things existing
unperceived or unconceived – such as objects far away in space and time. But
Berkeley is ready with his response, namely that just as one cannot see a thing
that is at the same time unseen, so it makes no sense to claim to conceive a
thing which is unconceived; and since what is conceived exists as such in the
mind, so in conceiving of something ‘unconceived’ one is not in fact conceiv-
ing of something outside the mind itself.^15
One may respond to Berkeley’s overall argument by drawing on two dis-
tinctions, each of which serves to disambiguate innocent and threatening
interpretations of such claims as that thought involves ideas, and that what is
conceived is ipso facto in the mind of a thinker. The first is between ideas or
concepts as media, and as objectsof thought. In the Summa Theologiae Aquinas
writes that ‘ideas stand in relation to the intellect as that by which the intel-
lect thinks and not as what is thought of ’.^16 Secondly, it is one thing to be
spatially present or contiguous and another to be cognitively so. Conjoining