A Treatise of Human Nature | Page 9

evident consequence of the
division of ideas into simple and complex. Where-ever the imagination perceives a
difference among ideas, it can easily produce a separation.

SECT. IV. OF THE CONNEXION OR ASSOCIATION OF IDEAS.
As all simple ideas may be separated by the imagination, and may be united again in
what form it pleases, nothing would be more unaccountable than the operations of that
faculty, were it not guided by some universal principles, which render it, in some
measure, uniform with itself in all times and places. Were ideas entirely loose and
unconnected, chance alone would join them; and it is impossible the same simple ideas
should fall regularly into complex ones (as they Commonly do) without some bond of
union among them, some associating quality, by which one idea naturally introduces
another. This uniting principle among ideas is not to be considered as an inseparable
connexion; for that has been already excluded from the imagination: Nor yet are we to
conclude, that without it the mind cannot join two ideas; for nothing is more free than
that faculty: but we are only to regard it as a gentle force, which commonly prevails, and
is the cause why, among other things, languages so nearly correspond to each other;
nature in a manner pointing out to every one those simple ideas, which are most proper to
be united in a complex one. The qualities, from which this association arises, and by
which the mind is after this manner conveyed from one idea to another, are three, viz.
RESEMBLANCE, CONTIGUITY in time or place, and CAUSE and EFFECT.
I believe it will not be very necessary to prove, that these qualities produce an association
among ideas, and upon the appearance of one idea naturally introduce another. It is plain,
that in the course of our thinking, and in the constant revolution of our ideas, our
imagination runs easily from one idea to any other that resembles it, and that this quality
alone is to the fancy a sufficient bond and association. It is likewise evident that as the
senses, in changing their objects, are necessitated to change them regularly, and take
them as they lie CONTIGUOUS to each other, the imagination must by long custom
acquire the same method of thinking, and run along the parts of space and time in
conceiving its objects. As to the connexion, that is made by the relation of cause and
effect, we shall have occasion afterwards to examine it to the bottom, and therefore shall
not at present insist upon it. It is sufficient to observe, that there is no relation, which
produces a stronger connexion in the fancy, and makes one idea more readily recall

another, than the relation of cause and effect betwixt their objects.
That we may understand the full extent of these relations, we must consider, that two
objects are connected together in the imagination, not only when the one is immediately
resembling, contiguous to, or the cause of the other, but also when there is interposed
betwixt them a third object, which bears to both of them any of these relations. This may
be carried on to a great length; though at the same time we may observe, that each
remove considerably weakens the relation. Cousins in the fourth degree are connected by
causation, if I may be allowed to use that term; but not so closely as brothers, much less
as child and parent. In general we may observe, that all the relations of blood depend
upon cause and effect, and are esteemed near or remote, according to the number of
connecting causes interposed betwixt the persons.
Of the three relations above-mentioned this of causation is the most extensive. Two
objects may be considered as placed in this relation, as well when one is the cause of any
of the actions or motions of the other, as when the former is the cause of the existence of
the latter. For as that action or motion is nothing but the object itself, considered in a
certain light, and as the object continues the same in all its different situations, it is easy
to imagine how such an influence of objects upon one another may connect them in the
imagination.
We may carry this farther, and remark, not only that two objects are connected by the
relation of cause and effect, when the one produces a motion or any action in the other,
but also when it has a power of producing it. And this we may observe to be the source of
all the relation, of interest and duty, by which men influence each other in society, and
are placed in the ties of government and subordination. A master is such-a-one as by his
situation, arising either from force or