An Enquiry Concerning Human Understanding HTML version

that no other effect, in such particular circumstances, could possibly have resulted from
it. The degree and direction of every motion is, by the laws of nature, prescribed with
such exactness that a living creature may as soon arise from the shock of two bodies as
motion in any other degree or direction than what is actually produced by it. Would we,
therefore, form a just and precise idea of necessity, we must consider whence that idea
arises when we apply it to the operation of bodies.
It seems evident that, if all the scenes of nature were continually shifted in such a manner
that no two events bore any resemblance to each other, but every object was entirely new,
without any similitude to whatever had been seen before, we should never, in that case,
have attained the least idea of necessity, or of a connexion among these objects. We
might say, upon such a supposition, that one object or event has followed another; not
that one was produced by the other. The relation of cause and effect must be utterly
unknown to mankind. Inference and reasoning concerning the operations of nature
would, from that moment, be at an end; and the memory and senses remain the only
canals, by which the knowledge of any real existence could possibly have access to the
mind. Our idea, therefore, of necessity and causation arises entirely from the uniformity
observable in the operations of nature, where similar objects are constantly conjoined
together, and the mind is determined by custom to infer the one from the appearance of
the other. These two circumstances form the whole of that necessity, which we ascribe to
matter. Beyond the constant conjunction of similar objects, and the consequent inference
from one to the other, we have no notion of any necessity or connexion.
If it appear, therefore, that all mankind have ever allowed, without any doubt or
hesitation, that these two circumstances take place in the voluntary actions of men, and in
the operations of mind; it must follow, that all mankind have ever agreed in the doctrine
of necessity, and that they have hitherto disputed, merely for not understanding each
65. As to the first circumstance, the constant and regular conjunction of similar events,
we may possibly satisfy ourselves by the following considerations. It is universally
acknowledged that there is a great uniformity among the actions of men, in all nations
and ages, and that human nature remains still the same, in its principles and operations.
The same motives always produce the same actions. The same events follow from the
same causes. Ambition, avarice, self-love, vanity, friendship, generosity, public spirit:
these passions, mixed in various degrees, and distributed through society, have been,
from the beginning of the world, and still are, the source of all the actions and enterprises,
which have ever been observed among mankind. Would you know the sentiments,
inclinations, and course of life of the Greeks and Romans? Study well the temper and
actions of the French and English: You cannot be much mistaken in transferring to the
former most of the observations which you have made with regard to the latter. Mankind
are so much the same, in all times and places, that history informs us of nothing new or
strange in this particular. Its chief use is only to discover the constant and universal
principles of human nature, by showing men in all varieties of circumstances and
situations, and furnishing us with materials from which we may form our observations
and become acquainted with the regular springs of human action and behaviour. These
records of wars, intrigues, factions, and revolutions, are so many collections of