3.  Judgement or assent to Probability, supplies our want of Knowledge.

The faculty which God has given man to supply the want of clear and certain knowledge, in cases where that cannot be had, is judgement:  whereby the mind takes its ideas to agree or disagree; or, which is the same, any proposition to be true or false, without perceiving a demonstrative evidence in the proofs.  The mind sometimes exercises this judgment out of necessity, where demonstrative proofs and certain knowledge are not to be had; and sometimes out of laziness, unskilfulness, or haste, even where demonstrative and certain proofs are to be had.  Men often stay not warily to examine the agreement or disagreement of two ideas, which they are desirous or concerned to know; but, either incapable of such attention as is requisite in a long train of gradations, or impatient of delay, lightly cast their eyes on, or wholly pass by the proofs; and so, without making out the demonstration, determine of the agreement or disagreement of two ideas, as it were by a view of them as they are at a distance, and take it to be the one or the other, as seems most likely to them upon such a loose survey.  This faculty of the mind, when it is exercised immediately about things, is called judgement; when about truths delivered in words, is most commonly called assent or dissent:  which being the most usual way, wherein the mind has occasion to employ this faculty, I shall, under these terms, treat of it, as feast liable in our language to equivocation.

4.  Judgement is the presuming Things to be so, without perceiving it.

Thus the mind has two faculties conversant (about truth and falsehood):—­

First, knowledge, whereby it certainly perceives, and is undoubtedly satisfied of the agreement or disagreement of any ideas.

Secondly, judgement, which is the putting ideas together, or separating them from one another in the mind, when their certain agreement or disagreement is not perceived, but presumed to be so; which is, as the word imports, taken to be so before it certainly appears.  And if it so unites or separates them as in reality things are, it is right judgement.

CHAPTER XV.  OF PROBABILITY.

1.  Probability is the appearance of Agreement upon fallible Proofs.

As demonstration is the showing the agreement or disagreement of two ideas, by the intervention of one or more proofs, which have a constant, immutable, and visible connexion one with another; so probability is nothing but the appearance of such an agreement or disagreement, by the intervention of proofs, whose connexion is not constant and immutable, or at least is not perceived to be so, but is, or appears for the most part to be so, and is enough to induce the mind to judge the proposition to be true or false, rather than the contrary.  For example:  in the demonstration