SECT. III. WHY A CAUSE IS ALWAYS NECESSARY.


To begin with the first question concerning the necessity of a cause:
It is a general maxim in philosophy, that whatever begins to exist, must
have a cause of existence. This is commonly taken for granted in all
reasonings, without any proof given or demanded. It is supposed to be
founded on intuition, and to be one of those maxims, which though they may
be denyed with the lips, it is impossible for men in their hearts really
to doubt of. But if we examine this maxim by the idea of knowledge
above-explained, we shall discover in it no mark of any such intuitive
certainty; but on the contrary shall find, that it is of a nature quite
foreign to that species of conviction.

All certainty arises from the comparison of ideas, and from the discovery
of such relations as are unalterable, so long as the ideas continue the
same. These relations are RESEMBLANCE, PROPORTIONS IN QUANTITY AND
NUMBER, DEGREES OF ANY QUALITY, and CONTRARIETY; none of which are
implyed in this proposition, Whatever has a beginning has also a cause of
existence. That proposition therefore is not intuitively certain. At
least any one, who would assert it to be intuitively certain, must deny
these to be the only infallible relations, and must find some other
relation of that kind to be implyed in it; which it will then be time
enough to examine.

But here is an argument, which proves at once, that the foregoing
proposition is neither intuitively nor demonstrably certain. We can never
demonstrate the necessity of a cause to every new existence, or new