4. If you wonder what organs of sense can be excited into motion, when you
call up the ideas of wisdom or benevolence, which Mr. Locke has termed
abstracted ideas; I ask you by what organs of sense you first became
acquainted with these ideas? And the answer will be reciprocal; for it is
certain that all our ideas were originally acquired by our organs of sense;
for whatever excites our perception must be external to the organ that
perceives it, and we have no other inlets to knowledge but by our
perceptions: as will be further explained in Section XIV. and XV. on the
Productions and Classes of Ideas.

VII. If our recollection or imagination be not a repetition of animal
movements, I ask, in my turn, What is it? You tell me it consists of images
or pictures of things. Where is this extensive canvas hung up? or where are
the numerous receptacles in which those are deposited? or to what else in
the animal system have they any similitude?

That pleasing picture of objects, represented in miniature on the retina of
the eye, seems to have given rise to this illusive oratory! It was forgot
that this representation belongs rather to the laws of light, than to those
of life; and may with equal elegance be seen in the camera obscura as in
the eye; and that the picture vanishes for ever, when the object is
withdrawn.

* * * * *

SECT. IV.

LAWS OF ANIMAL CAUSATION.

I. The fibres, which constitute the muscles and organs of sense, possess a