For every man
is able to perceive with absolute certainty that he himself exists, that
God must exist, and that finite beings other than himself exist;--the
first of these perceptions being awakened by all our ideas, the second
as the consequence of perception of the first, and the last in the
reception of our simple ideas of sense (chh. i. Section 7; ii. Section
14; iii. Section 21; iv, ix-xi). Agreement of the third sort, of
necessary coexistence of simple ideas as qualities and powers in
particular substances, with which all physical inquiry is concerned,
lies beyond human Knowledge; for here the nominal and real essences are
not coincident: general propositions of this sort are determined by
analogies of experience, in judgments that are more or less probable:
intellectually necessary science of nature presupposes Omniscience;
man's interpretations of nature have to turn upon presumptions of
Probability (chh. iii. Sections 9-17; iv. SectionS 11-17; vi, xiv-xvi).
In forming their stock of Certainties and Probabilities men employ the
faculty of reason, faith in divine revelation, and enthusiasm (chh.
xvii-xix); much misled by the last, as well as by other causes of 'wrong
assent' (ch. xx), when they are at work in 'the three great provinces of
the intellectual world' (ch. xxi), concerned respectively with (1)
'things as knowable' (physica); (2) 'actions as they depend on us in
order to happiness' (practica); and (3) methods for interpreting the
signs of what is, and of what ought to be, that are presented in our
ideas and words (logica).

CHAPTER I.

OF KNOWLEDGE IN GENERAL.

1. Our Knowledge conversant about our Ideas only.

Since the mind, in all its thoughts and reasonings, hath no other
immediate object but its own ideas, which it alone does or can
contemplate, it is evident that our knowledge is only conversant about
them.

2. Knowledge is the Perception of the Agreement or Disagreement of two
Ideas.

KNOWLEDGE then seems to me to be nothing but THE PERCEPTION OF THE
CONNEXION OF AND AGREEMENT, OR DISAGREEMENT AND REPUGNANCY OF ANY OF OUR
IDEAS. In this alone it consists.

Where this perception is, there is knowledge, and where it is not,
there, though we may fancy, guess, or believe, yet we always come short
of knowledge. For when we know that white is not black, what do we
else but perceive, that these two ideas do not agree? When we possess
ourselves with the utmost security of the demonst