ough to find certain truth in everything which we have occasion to
consider; most of the propositions we think, reason, discourse--nay, act
upon, are such as we cannot have undoubted knowledge of their truth:
yet some of them border so near upon certainty, that we make no act,
according to the assent, as resolutely as if they were infallibly
demonstrated, and that our knowledge of them was perfect and certain.
But there being degrees herein, from the very neighbourhood of certainty
and demonstration, quite down to improbability and unlikeness, even to
the confines of impossibility; and also degrees of assent from full
assurance and confidence, quite down to conjecture, doubt, and distrust:
I shall come now, (having, as I think, found out THE BOUNDS OF HUMAN
KNOWLEDGE AND CERTAINTY,) in the next place, to consider THE SEVERAL
DEGREES AND GROUNDS OF PROBABILITY, AND ASSENT OR FAITH.

3. Being that which makes us presume Things to be true, before we know
them to be so.

Probability is likeliness to be true, the very notation of the word
signifying such a proposition, for which there be arguments or proofs to
make it pass, or be received for true. The entertainment the mind gives
this sort of propositions is called BELIEF, ASSENT, or OPINION, which is
the admitting or receiving any proposition for true, upon arguments or
proofs that are found to persuade us to receive it as true, without
certain knowledge that it is so. And herein lies the difference between
PROBABILITY and CERTAINTY, FAITH, and KNOWLEDGE, that in all the parts
of knowledge there is intuition; each immediate idea, each step has its
visible and certain connexion: in belief, not so. That which makes me
believe, is something extraneous to the thing I believe; something not
evidently joined on both sides to, and so not manifestly showing the
agreement or disagreement of those ideas that are under consideration.

4. The Grounds of Probability are two: Conformity with our own
Experience, or the Testimony of others.

Probability then, being to supply the defect of our knowledge, and to
guide us where that fails, is always conversant about propositions
whereof we have no certainty, but only some inducements to receive them
for true. The grounds of it are, in short, these two following:--

First, The conformity of anything with our own knowledge, observation,
and experience.

Secondly, The testimony of others, vouching their observation and
experience. In