An Enquiry Concerning Human Understanding HTML version

III. Of The Association Of Ideas
18. It is evident that there is a principle of connexion between the different thoughts or
ideas of the mind, and that, in their appearance to the memory or imagination, they
introduce each other with a certain degree of method and regularity. In our more serious
thinking or discourse this is so observable that any particular thought, which breaks in
upon the regular tract or chain of ideas, is immediately remarked and rejected. And even
in our wildest and most wandering reveries, nay in our very dreams, we shall find, if we
reflect, that the imagination ran not altogether at adventures, but that there was still a
connexion upheld among the different ideas, which succeeded each other. Were the
loosest and freest conversation to be transcribed, there would immediately be observed
something which connected it in all its transitions. Or where this is wanting, the person
who broke the thread of discourse might still inform you, that there had secretly revolved
in his mind a succession of thought, which had gradually led him from the subject of
conversation. Among different languages, even where we cannot suspect the least
connexion or communication, it is found, that the words, expressive of ideas, the most
compounded, do yet nearly correspond to each other: a certain proof that the simple
ideas, comprehended in the compound ones, were bound together by some universal
principle, which had an equal influence on all mankind.
19. Though it be too obvious to escape observation, that different ideas are connected
together; I do not find that any philosopher has attempted to enumerate or class all the
principles of association; a subject, however, that seems worthy of curiosity. To me, there
appear to be only three principles of connexion among ideas, namely, Resemblance,
Contiguity in time or place, and Cause or Effect.
That these principles serve to connect ideas will not, I believe, be much doubted. A
picture naturally leads our thoughts to the original2: the mention of one apartment in a
building naturally introduces an enquiry or discourse concerning the others3: and if we
think of a wound, we can scarcely forbear reflecting on the pain which follows it4. But
that this enumeration is complete, and that there are no other principles of association
except these, may be difficult to prove to the satisfaction of the reader, or even to a man's
own satisfaction. All we can do, in such cases, is to run over several instances, and
examine carefully the principle which binds the different thoughts to each other, never
stopping till we render the principle as general as possible5. The more instances we
examine, and the more care we employ, the more assurance shall we acquire, that the
enumeration, which we form from the whole, is complete and entire.