proved it
sufficiently by the foregoing arguments.

Since it is not from knowledge or any scientific reasoning, that we
derive the opinion of the necessity of a cause to every new production,
that opinion must necessarily arise from observation and experience. The
next question, then, should naturally be, how experience gives rise to
such a principle? But as I find it will be more convenient to sink this
question in the following, Why we conclude, that such particular
causes must necessarily have such particular erects, and why we form
an inference from one to another? we shall make that the subject of our
future enquiry. It will, perhaps, be found in the end, that the same
answer will serve for both questions.

SECT. IV. OF THE COMPONENT PARTS OF OUR REASONINGS CONCERNING CAUSE AND EFFECT.

Though the mind in its reasonings from causes or effects carries its
view beyond those objects, which it sees or remembers, it must never
lose sight of them entirely, nor reason merely upon its own ideas,
without some mixture of impressions, or at least of ideas of the memory,
which are equivalent to impressions. When we infer effects from causes,
we must establish the existence of these causes; which we have only
two ways of doing, either by an immediate perception of our memory or
senses, or by an inference from other causes; which causes again we must
ascertain in the same manner, either by a present impression, or by an
inference from their causes, and so on, till we arrive at some object,
which we see or remember. It is impossible for us to carry on our
inferences IN INFINITUM; and the only thing, that can stop them, is an
impression of the memory or senses, beyond which there is no room for
doubt or enquiry.

To give an instance of this, we may chuse any point of history, and
consider for what reason we either believe or reject it. Thus we believe
that Caesar was killed in the senate-house on the ides of March; and
that because this fact is established on the unanimous testimony of
historians, who agree to assign this precise time and place to that
event. Here are certain characters and letters present either to our
memory or senses; which characters we likewise remember to have been
used as the signs of certain ideas; and these ideas were either in the
minds of such as were immediately present at that action, and received
the ideas directly from its existence; or they were derived from the
testimony of others, and