either innate or due to misconceptions - that is, to some external
influence. (2) Such persons are not conscious of themselves.
(3) If they affirm or doubt anything, they know not that they
affirm or doubt: they say that they know nothing, and they say
that they are ignorant of the very fact of their knowing nothing.
(4) Even this they do not affirm absolutely, they are afraid of
confessing that they exist, so long as they know nothing;
in fact, they ought to remain dumb, for fear of haply supposing
which should smack of truth.

[48] (1) Lastly, with such persons, one should not speak of
sciences: for, in what relates to life and conduct, they are
compelled by necessity to suppose that they exist, and seek
their own advantage, and often affirm and deny, even with an
oath. (2) If they deny, grant, or gainsay, they know not that
they deny, grant, or gainsay, so that they ought to be
regarded as automata, utterly devoid of intelligence.

[49] (1) Let us now return to our proposition. (2) Up to the present,
we have, first, defined the end to which we desire to direct all our
thoughts; secondly, we have determined the mode of perception best
adapted to aid us in attaining our perfection; thirdly, we have
discovered the way which our mind should take, in order to make a good
beginning - namely, that it should use every true idea as a standard in
pursuing its inquiries according to fixed rules. (49:3) Now, in order
that it may thus proceed, our method must furnish us, first, with a
means of distinguishing a true idea from all other perceptions, and
enabling the mind to avoid the latter; secondly, with rules for
perceiving unknown things according to the standard of the true idea;
thirdly, with an order which enables us to avoid useless labor.