The consequence I shall draw from this may, at first sight, appear a
mere sophism; but upon the least examination will be found solid and
satisfactory. I say then, that since we may suppose, but never can
conceive a specific deference betwixt an object and impression; any
conclusion we form concerning the connexion and repugnance of
impressions, will not be known certainly to be applicable to objects;
but that on the other hand, whatever conclusions of this kind we form
concerning objects, will most certainly be applicable to impressions.
The reason is not difficult. As an object is supposed to be different
from an impression, we cannot be sure, that the circumstance, upon
which we found our reasoning, is common to both, supposing we form the
reasoning upon the impression. It is still possible, that the object
may differ from it in that particular. But when we first form our
reasoning concerning the object, it is beyond doubt, that the same
reasoning must extend to the impression: And that because the quality
of the object, upon which the argument is founded, must at least be
conceived by the mind; and could not be conceived, unless it were
common to an impression; since we have no idea but what is derived from
that origin. Thus we may establish it as a certain maxim, that we can
never, by any principle, but by an irregular kind[11] form the
coherence of our perceptions.] of reasoning from experience, discover a
connexion or repugnance betwixt objects, which extends not to
impressions; though the inverse proposition may not be equally true,
that all the discoverable relations of impressions are common to
objects.
[11] Such as that of Sect. 2, form the coherence of our
perceptions.