wever common, are neither universal nor
unavoidable in human nature. The modern philosophy pretends to be
entirely free from this defect, and to arise only from the solid,
permanent, and consistent principles of the imagination. Upon what
grounds this pretension is founded must now be the subject of our
enquiry.

The fundamental principle of that philosophy is the opinion concerning
colours, sounds, tastes, smells, heat and cold; which it asserts to
be nothing but impressions in the mind, derived from the operation of
external objects, and without any resemblance to the qualities of the
objects. Upon examination, I find only one of the reasons commonly
produced for this opinion to be satisfactory, viz. that derived from the
variations of those impressions, even while the external object, to all
appearance, continues the same. These variations depend upon several
circumstances. Upon the different situations of our health: A man in a
malady feels a disagreeable taste in meats, which before pleased him the
most. Upon the different complexions and constitutions of men That seems
bitter to one, which is sweet to another. Upon the difference of their
external situation and position: Colours reflected from the clouds
change according to the distance of the clouds, and according to the
angle they make with the eye and luminous body. Fire also communicates
the sensation of pleasure at one distance, and that of pain at another.
Instances of this kind are very numerous and frequent.

The conclusion drawn from them, is likewise as satisfactory as can
possibly be imagined. It is certain, that when different impressions of
the same sense arise from any object, every one of these impressions has
not a resembling quality existent in the object. For as the same object
cannot, at the same time, be endowed with different qualities of the
same sense, and as the same quality cannot resemble impressions entirely
different; it evidently follows, that many of our impressions have
no external model or archetype. Now from like effects we presume like
causes. Many of the impressions of colour, sound, &c. are confest to be
nothing but internal existences, and to arise from causes, which no ways
resemble them. These impressions are in appearance nothing different
from the other impressions of colour, sound, &c. We conclude, therefore,
that they are, all of them, derived from a like origin.

This principle being once admitted, all the other doctri