Even after we distinguish our perceptions from our objects, it will appear presently, that we are still incapable of reasoning from the existence of one to that of the other: So that upon the whole our reason neither does, nor is it possible it ever should, upon any supposition, give us an assurance of the continued and distinct existence of body.

That opinion must be entirely owing to the IMAGINATION: which must now be the subject of our enquiry.
Since all impressions are internal and perishing existences, and appear as such, the notion of their distinct and continued existence must arise from a concurrence of some of their qualities with the qualities of the imagination, and since this notion does not extend to all of them, it must arise from certain qualities peculiar to some impressions.

It will therefore be easy for us to discover these qualities by a comparison of the impressions, to which we attribute a distinct and continued existence, with those, which we regard as internal and perishing.
We may observe, then, that it is neither upon account of the involuntariness of certain impressions, as is commonly supposed, nor of their superior force and violence, that we attribute to them a reality, and continued existence, which we refuse to others, that are voluntary or feeble.

For it is evident our pains and pleasures, our passions and affections, which we never suppose to have any existence beyond our perception, operate with greater violence, and are equally involuntary, as the impressions of figure and extension, colour and sound, which we suppose to be permanent beings.

The heat of a fire, when moderate, is supposed to exist in the fire; but the pain, which it causes upon a near approach, is not taken to have any being, except in the perception.
These vulgar opinions, then, being rejected, we must search for some other hypothesis, by which we may discover those peculiar qualities in our impressions, which makes us attribute to them a distinct and continued existence.
After a little examination, we shall find, that all those objects, to which we attribute a continued existence, have a peculiar constancy, which distinguishes them from the impressions, whose existence depends upon our perception.