XXV. This is the utmost extent to which the matter of doubting can be carried. But by way of answer to it, I shall reply, that the persuasion we have of being awake when we are dreaming, differs greatly from that we have of being awake, when we actually are so. This last is a clear, firm, determined, invincible persuasion, and such a one, as is required to constitute experimental evidence of the certainty of the fact; which it does in such a manner, that notwithstanding all the reflections we can make, and all the doubts and difficulties we can suggest, our assent to, and persuasion of the truth of it, remains firm and unshaken. On the contrary, when we are dreaming, our reflection is obscure, and the persuasion produced in consequence of it, feeble and wavering; which will evidently appear to be the case, if in the course of our dreaming, it should occur to us to make a doubtful reflection, whether what our imagination represents to us is reality, or only a dream; and the result to a man who was to do this would be, a faint and doubtful determination of whether he actually dreams, or only believes he is dreaming, and he would remain in a state of doubt, whether what his fancy represents to him be real or not. I say in all these cases, his decision of the matter, would not be resolute and firm, but wavering and languid. This doubt of whether I am asleep or not, often occurs to me in dreams, which never fails to produce one of the two following effects, either to certify to me that I am dreaming, or to make me suspend my assent to the fact. And I will venture to assure any one, who shall persist for a few moments, in proposing these doubts to himself when he is dreaming, that he will find the same thing happen to him.