Elements of the philosophy of the human mind. By Dugald Stewart. Rev. and abridged, with critical and explanatory notes, for the use of colleges and schools. By Francis Bowen ...

200 DREAMIING.
Baxter, that it gave rise to his very whimsical theory, in which
he ascribes dreams to the immediate influence of separate spirits
on the mind.
3. If the influence of the will be suspended during sleep, the
conceptions which we then form of sensible objects will be
attended with a belief of their real existence, as much as the
perception of the same objects is while we are awake.
In treating of the power of conception, I formerly observed,
that our belief of the separate and independent existence of the
objects of our perceptions, is the result of experience; which
teaches us that these perceptions do not depend on our will. If
I open my eyes, I cannot prevent myself from seeing the prospect before me. The case is different with respect to our conceptions. While they occupy the mind, to the exclusion of
every thing else, I endeavored to show, that they are always
accompanied with belief: but as we can banish them from the
mind, during our waking hours, at pleasure; and as the momentary belief which they produce, is continually checked by the
surrounding objects of our perceptions, we learn to consider
them as fictions of our own creation; and, excepting in some
accidental cases, pay no regard to them in the conduct of life.
If the doctrine, however, formerly stated with respect to conception be just, and if, at the samre tilne, it be allowed, that sleep
suspends the influence of the will over the train of our thoughts,
we should naturally be led to expect, that the same belief which
accompanies conception while we are awake, should accompany
the perceptions which occur to us in our dreams. It is scarcely
necessary for me to remark, how strikingly this conclusion coincides with acknowledged facts.
May it not be considered as some confirmation of the foregoing
doctrine, that when opium fails in producing complete sleep, it
commonly produces one of the effects of sleep, by suspending
the activity of the mind, and throwing it into a revery; and that
while we are in this state, our conceptions frequently affect us
nearly in the same manner, as if' the objects conceived were
present to our senses? —- (See the Baron de Tott's Account of
the Opium-takers at Contantinople.)