affirm that it froze in England the last winter, or that there were swallows seen there in the summer, I think a man could almost as little doubt of it as that seven and four are eleven.  The first, therefore, and highest degree of probability, is, when the general consent of all men, in all ages, as far as it can be known, concurs with a man’s constant and never-failing experience in like cases, to confirm the truth of any particular matter of fact attested by fair witnesses:  such are all the stated constitutions and properties of bodies, and the regular proceedings of causes and effects in the ordinary course of nature.  This we call an argument from the nature of things themselves.  For what our own and other men’s constant observation has found always to be after the same manner, that we with reason conclude to be the effect of steady and regular causes; though they come not within the reach of our knowledge.  Thus, That fire warmed a man, made lead fluid, and changed the colour or consistency in wood or charcoal; that iron sunk in water, and swam in quicksilver:  these and the like propositions about particular facts, being agreeable to our constant experience, as often as we have to do with these matters; and being generally spoke of (when mentioned by others) as things found constantly to be so, and therefore not so much as controverted by anybody—­we are put past doubt that a relation affirming any such thing to have been, or any predication that it will happen again in the same manner, is very true.  These probabilities rise so near to certainty, that they govern our thoughts as absolutely, and influence all our actions as fully, as the most evident demonstration; and in what concerns us we make little or no difference between them and certain knowledge.  Our belief, thus grounded, rises to assurance.

7.  II.  Unquestionable Testimony, and our own Experience that a thing is for the most part so, produce Confidence.

The next degree of probability is, when I find by my own experience, and the agreement of all others that mention it, a thing to be for the most part so, and that the particular instance of it is attested by many and undoubted witnesses:  v.g. history giving us such an account of men in all ages, and my own experience, as far as I had an opportunity to observe, confirming it, that most men prefer their private advantage to the public:  if all historians that write of Tiberius, say that Tiberius did so, it is extremely probable.  And in this case, our assent has a sufficient foundation to raise itself to a degree which we may call confidence.

8.  III.  Fair Testimony, and the Nature of the Thing indifferent, produce unavoidable Assent.