Yet before I had sufficiently considered them I might be uncertain,
or even entertain a wrong conception of the geometrical relations
and imagine it to be certainly right. No one knew better than
Spinoza how easy it is to hold confused and erroneous beliefs with
absolute confidence. Some of the current notions in philosophy
and psychology which he makes the objects of his most unsparing
attack are precisely those which have been most commonly main-
tained on the ground that they are principles given by conscious-
ness as clear, ultimate, and self-evident.
At the same time there is no reason to doubt that Spinoza did
underrate (as almost all constructive philosophers have underrated)
the difficulty of ascertaining what the ultimate data of sense and
thought really are ; he nowhere undertakes the analysis of these
data, nor does he separate it from the business of ascertaining
concrete truth in particular cases. Descartes' own testimony is
express that he thought the whole body of possible knowledge to
lie, generally if not in detail, within a moderate compass, and to
be deducible from principles which might be finally settled in a
single generation, when once the problem of method was solved.
Spinoza is not so explicit, but it seems probable that his expecta-
tions were of the same kind. For men in this sanguine frame of
mind it was natural also to underrate the difficulty of procuring
acceptance among mankind for the conceptions which to them
appeared to shine with the hght of evident and self-justifying
truth. This kind of excessive hope, however, is capable of being
dashed by experience in all but incorrigible visionaries ; and while
it appears, though not extravagantly, in the fragment De Intellectus
Emendatione^ no sign of it is left in the Ethics.
