o be determined only on the ground of the operation or
non-operation of the means of right knowledge; while on the other hand,
the operation and non-operation of the means of right knowledge are not
to be made dependent on preconceived possibilities or impossibilities.
Possible is whatever is apprehended by perception or some other means of
proof; impossible is what is not so apprehended. Now the external things
are, according to their nature, apprehended by all the instruments of
knowledge; how then can you maintain that they are not possible, on the
ground of such idle dilemmas as that about their difference or
non-difference from atoms?--Nor, again, does the non-existence of
objects follow from the fact of the ideas having the same form as the
objects; for if there were no objects the ideas could not have the forms
of the objects, and the objects are actually apprehended as
external.--For the same reason (i.e. because the distinction of thing
and idea is given in consciousness) the invariable concomitance of idea
and thing has to be considered as proving only that the thing
constitutes the means of the idea, not that the two are identical.
Moreover, when we are conscious first of a pot and then of a piece of
cloth, consciousness remains the same in the two acts while what varies
are merely the distinctive attributes of consciousness; just as when we
see at first a black and then a white cow, the distinction of the two
perceptions is due to the varying blackness and whiteness while the
generic character of the cow remains the same. The difference of the one
permanent factor (from the two--or more--varying factors) is proved
throughout by the two varying factors, and vice versa the difference of
the latter (from the permanent factor) by the presence of the one
(permanent factor). Therefore thing and idea are distinct. The same view
is to be held with regard to the perception and the remembrance of a
jar; there also the perception and the remembrance only are distinct
while the jar is one and the same; in the same way as when conscious of
the smell of milk and the taste of milk we are conscious of the smell
and taste as different things but of the milk itself as one only.

Further, two ideas which occupy different moments of time and pass away
as soon as they have become objects of consciousness cannot
apprehend--or be apprehended by--each other. From this it follows that
certain doctrines forming part of the Bauddha sys