st, although the
sceptic reduces it to a mere blind custom or 'association of ideas.' Now
Reid argues that the belief, whatever its nature, is not and cannot be
derived from the sensations. We do not construct the visible and
tangible world, for example, simply out of impressions made upon the
senses of sight and touch. To prove this, he examines what are the
actual data provided by these senses, and shows, or tries to show, that
we cannot from them alone construct the world of space and geometry.
Hence, if we consider experience impartially and without preconception,
we find that it tells us something which is not given by the senses. The
senses are not the material of our perceptions, but simply give the
occasions upon which our belief is called into activity. The sensation
is no more like the reality in which we believe than the pain of a wound
is like the edge of the knife. Perception tells us directly and
immediately, without the intervention of ideas, that there is, as we all
believe, a real external world.

Reid was a vigorous reasoner, and credit has been given to him by some
disciples of Kant's doctrine of time and space. Schopenhauer[165] says
that Reid's 'excellent work' gives a complete 'negative proof of the
Kantian truths'; that is to say, that Reid proves satisfactorily that we
cannot construct the world out of the sense-given data alone. But,
whereas Kant regards the senses as supplying the materials moulded by
the perceiving mind, Reid regards them as mere stimuli exciting certain
inevitable beliefs. As a result of Reid's method, then, we have
'intuitions.' Reid's essential contention is that a fair examination of
experience will reveal certain fundamental beliefs, which cannot be
explained as mere manifestations of the sensations, and which, by the
very fact that they are inexplicable, must be accepted as an
'inspiration.'[166] Reid professes to discover these beliefs by
accurately describing facts. He finds them there as a chemist finds an
element. The 'intuition' is made by substituting for 'ideas' a
mysterious and inexplicable connection between the mind and matter.[167]
The chasm exists still, but it is somehow bridged by a quasi-miracle.
Admitting, therefore, that Reid shows a gap to exist in the theory, his
result remains 'negative.' The philosopher will say that it is not
enough to assert a principle dogmatically without showing its place in a
reasoned system of thought. The psychologist, on the