BOOK I PART IV
related qualities is readily considered as one
continued object, existing without any varia-
tion. The smooth and uninterrupted progress
of the thought, being alike in both cases, read-
ily deceives the mind, and makes us ascribe an
identity to the changeable succession of con-
nected qualities.
But when we alter our method of consid-
ering the succession, and instead of traceing
it gradually through the successive points of
time, survey at once Any two distinct peri-
ods of its duration, and compare the differ-
ent conditions of the successive qualities; in
that case the variations, which were insensi-
ble when they arose gradually, do now appear
of consequence, and seem entirely to destroy
the identity. By this means there arises a kind
of contrariety in our method of thinking, from