experienced their connexion: yet thus much seems undeniable, namely,
that the number of the visible feet being the same with that of the
tangible feet, I may from hence without any experience of sight
reasonably conclude that they represent or are connected with the feet
rather than the head. I say, it seems the idea of two visible feet will
sooner suggest to the mind the idea of two tangible feet than of one
head; so that the blind man upon first reception of the visive faculty
might know which were the feet or two, and which the head or one.

108. In order to get clear of this seeming difficulty we need only
observe that diversity of visible objects doth not necessarily infer
diversity of tangible objects corresponding to them. A picture painted
with great variety of colours affects the touch in one uniform manner; it
is therefore evident that I do not by any necessary consecution,
independent of experience, judge of the number of things tangible from
the number of things visible. I should not, therefore, at first opening
my eyes conclude that because I see two I shall feel two. How, therefore,
can I, before experience teaches me, know that the visible legs, because
two, are connected with the tangible legs, or the visible head, because
one, is connected with the tangible head? The truth is, the things I see
are so very different and heterogeneous from the things I feel that the
perception of the one would never have suggested the other to my
thoughts, or enabled me to pass the least judgment thereon, until I had
experienced their connexion.

109. But for a fuller illustration of this matter it ought to be
considered that number (however some may reckon it amongst the primary
qualities) is nothing fixed and settled, really existing in things
themselves. It is entirely the creature of the mind, considering either
an idea by itself, or any combination of ideas to which it gives one
name, and so makes it pass for an unit. According as the mind variously
combines its ideas the unit varies: and as the unit, so the number, which
is only a collection of units, doth also vary. We call a window one, a
chimney one, and yet a house in which there are many windows and many
chimneys hath an equal right to be called one, and many houses go to the
making of the city. In these and the like, instances it is evident the
unit constantly relates to the particular draughts the mind makes of its
ideas, to which it affixes names, and where