124 J.J. Haldane
[I]t will be easy for us to conceive any object to be non-existent this moment,
and existent the next, without conjoining to it the distinct idea of a cause or
productive principle. The separation, therefore, of the idea of a cause from that
of a beginning of existence, is plainly possible for the imagination; and con-
sequently the actual separation of these objects is so far possible, that it implies
no contradiction or absurdity; and is therefore incapable of being refuted by
any reasoning from mere ideas; without which ’tis impossible to demonstrate
the necessity of a cause.^19This short passage draws heavily on Hume’s epistemology and metaphysics,
both of which have been important ingredients in the modern philosoph-
ical case for atheism. Here, however, I am only concerned with the liberality
of the reasoning about what is possible and impossible. Hume takes it to
be sufficient to show that things can come into being without a cause that we
can ‘conceive’ this, i.e. imagine it, without contradiction. Hence no argument
from our mere ideas can refute the claim that things can begin to exist
uncaused. Clearly this implies the denial of the principle of sufficient reason
in even a weak form – for example, that where something comes to be,
including a change, there is something true to be said that renders it intelli-
gible, answering to the question ‘why?’ One response to Hume might pick up
his phrase ‘mere ideas’ and emphasize the element of ‘mereness’, conceding
that on some interpretation of this it may well be that no such ideas can serve
to refute the denial of the causal dependence of contingent existence but that
nothing of any serious interest follows. Suppose, for example, one were to
contrast ‘mere ideas’ with ‘adequate concepts’, it being a defining condition of
the latter (but not the former) that they are reality-reflecting and rationally
constrained; then while mere ideas might fail to reveal an impossibility of
causeless coming to be, thinking with adequate concepts does establish this.
The realist, be he a theist or not, has reason to maintain that there are
adequate concepts more than mere ideas, for otherwise general scepticism
and /or anti-realism become inescapable. Of itself this does not vindicate the
principle but it blocks part of an argument from imagination to fact.
Additionally, however, Hume offers no account of how we might deter-
mine the content of conceptions based on images and mere ideas. Try to test
his argument by imagining for yourself something popping into existence, or
changing, uncaused. You are sitting at an empty desk looking at its surface
and all of a sudden a book, or an apple, or a lump of unidentifiable matter
appears before you, or the desk top changes colour. That is imaginable,
but what is neither given nor required by the scenario is that the objects
have come to be without a cause, and that is not at all something one would
suppose. Rather one would ask ‘Where have they come from?’, ‘How
did they get here?’, ‘Who or what made them happen?’, and so on. In other
words once one moves from Hume’s abstractions to an actual example