repetition?  All we can say is that the known casts its shadow before; we project into unborn time the existing types, and the secret skill of nature intercepts the darkness of the future by ever suspending before our eyes, as it were in a mirror, a reflection of the past.  We really look at a blank before us, but the mind, full of the scene behind, sees it again in front....

What ground of reason, then, can we assign for our expectation that any part of the course of nature will the next moment be like what it has been up to this moment, i.e. for our belief in the uniformity of nature?  None.  No demonstrative reason can be given, for the contrary to the recurrence of a fact of nature is no contradiction.  No probable reason can be given, for all probable reasoning respecting the course of nature is founded upon this presumption of likeness, and therefore cannot be the foundation of it.  No reason can be given for this belief.  It is without a reason.  It rests upon no rational ground and can be traced to no rational principle.  Everything connected with human life depends upon this belief, every practical plan or purpose that we form implies it, every provision we make for the future, every safeguard and caution we employ against it, all calculation, all adjustment of means to ends, supposes this belief; it is this principle alone which renders our experience of the slightest use to us, and without it there would be, so far as we are concerned, no order of nature and no laws of nature; and yet this belief has no more producible reason for it than a speculation of fancy.  A natural fact has been repeated; it will be repeated:—­I am conscious of utter darkness when I try to see why one of these follows from the other:  I not only see no reason, but I perceive that I see none, though I can no more help the expectation than I can stop the circulation of my blood.  There is a premiss, and there is a conclusion, but there is a total want of connection between the two.  The inference, then, from the one of these to the other rests upon no ground of the understanding; by no search or analysis, however subtle or minute, can we extract from any corner of the human mind and intelligence, however remote, the very faintest reason for it.

Hume, who had urged with great force that miracles were contrary to that probability which is created by experience, had also said that this probability had no producible ground in reason; that, universal, unfailing, indispensable as it was to the course of human life, it was but an instinct which defied analysis, a process of thought and inference for which he vainly sought the rational steps.  There is no absurdity, though the greatest impossibility, in supposing this order to stop to-morrow; and, if the world ends at all, its end will be in an increasing degree improbable up to the very last moment.  But, if this whole ground of belief is in its own nature avowedly instinctive