296 NOTES. [BK. III.
than a simple impression or a single idea, there is liability to error, as was observed and exemplified in the case of a fluid, which, from being bitter and yellow, is at once assumed to be bile because those are the known qualities of that fluid. Many of our errors arise, no doubt, in like manner, from our not sufficiently scrutinising the impres-
sions derived from external objects.
Note 1, p. 135. It is then manifest that perception &c.] This is a conclusion drawn from the reasoning of a former chapter, and its purport is to shew that our senses enable us to judge even of privative conditions, as darkness and silence; and, further, that, being receptive of forms without matter, they can retain images, and so, through the sensorium recall objects after their with-
Note 2, p. 136. The action of the object of percep-
tion, &c.] It has been attempted, by some of the ancient commentators, to annex this to the preceding argument, and shew that, as sight must first be imbued with colour, so the hearing must, in order to perceive sounds, be first sensible of the actions of sonorous bodies. But the more obvious signification, and which is equally supported by the text, is, that there must be simultaneous-