in it includes more or less as
best suits its own ends and purposes. Whatever, therefore, the mind
considers as one, that is an unit. Every combination of ideas is
considered as one thing by the mind, and in token thereof is marked by
one name. Now, this naming and combining together of ideas is perfectly
arbitrary, and done by the mind in such sort as experience shows it to be
most convenient: without which our ideas had never been collected into
such sundry distinct combinations as they now are.

110. Hence it follows that a man born blind and afterwards, when grown
up, made to see, would not in the first act of vision parcel out the
ideas of sight into the same distinct collections that others do, who
have experienced which do regularly coexist and are proper to be bundled
up together under one name. He would not, for example, make into one
complex idea, and thereby esteem an unit, all those particular ideas
which constitute the visible head or foot. For there can be no reason
assigned why he should do so, barely upon his seeing a man stand upright
before him. There crowd into his mind the ideas which compose the visible
man, in company with all the other ideas of sight perceived at the same
time: but all these ideas offered at once to his view, he would not
distribute into sundry distinct combinations till such time as by
observing the motion of the parts of the man and other experiences he
comes to know which are to be separated and which to be collected
together.

111. From what hath been premised it is plain the objects of sight and
touch make, if I may so say, two sets of ideas which are widely different
from each other. To objects of either kind we indifferently attribute the
terms high and low, right and left, and suchlike, denoting the position
or situation of things: but then we must well observe that the position
of any object is determined with respect only to objects of the same
sense. We say any object of touch is high or low, according as it is more
or less distant from the tangible earth: and in like manner we denominate
any object of sight high or low in proportion as it is more or less
distant from the visible earth: but to define the situation of visible
things with relation to the distance they bear from any tangible thing,
or VICE VERSA, this were absurd and perfectly unintelligible. For all
visible things are equally in the mind, and take up no part of the
external space: and consequently are eq