Volition has no more power over thought when we are awake than sleeping; and, despite all metaphysical and psychological speculations, it cannot be demonstrated that the mind does not retain its full energies during sleep, only they cease to be regulated by judgment, and are not, to use Locke's words, under the rule and conduct of the understanding; and even on this opinion it has been fairly observed, that much of incongruity which is supposed to prove suspension of reason, and much of the wild discordancy of representation which appears to prevail during our sleep, may arise from the defect of memory when we are awake, that does not retain the impression of images which have passed across the mind in light and rapid succession, and which, therefore, exhibit but a partial and imperfect sketch of the picture that engaged the attention in sleep. The well-known fact that the impressions of our dreams are oftentimes more vivid and correct, when some time has elapsed, than on our awakening, tends to confirm this hypothesis; and these recollections are the more vivid when they bear any analogy to circumstances that come to pass. Sir Thomas Brown was of opinion that sleep was the waking of the soul; the ligation of sense, but the liberty of reason; and that our waking conceptions do not match the fancies of our sleep. He thus expresses himself in his Religio Medici: "At my nativity my ascendant was the watery sign of Scorpius; I was born in the planetary hour of Saturn, and I think I have a piece of that leaden planet in me. I am no way facetious, nor disposed for the mirth and galliardise of company; yet in one dream I can compose a whole comedy, behold the action, apprehend the jests, and laugh myself awake at the conceits thereof. Were my memory as faithful as my reason is then fruitful, I would never study but in my dreams, and this time also would I choose for my devotions; but our grosser memories have then so little hold of our abstracted understandings, that they forget the story, and can only relate to our awaked souls a confused and broken tale of that that hath passed."