Suppose he had a basket full of apples and, being worried that some of the
apples were rotten, wanted to take out the rotten ones to prevent the
rot spreading. How would he proceed? Would he not begin by tipping
the whole lot out of the basket? And would not the next step be to cast
his eye over each apple in turn, and pick up and put back in the basket
only those he saw to be sound, leaving the others? In just the same
way, those who have never philosophized correctly have various
opinions in their minds which they have begun to store up since
childhood, and which they therefore have reason to believe may in
many cases be false. They then attempt to separate the false beliefs
from the others, so as to prevent their contaminating the rest and
making the whole lot uncertain. Now the best way they can accomplish
this is to reject all their beliefs together in one go, as if they were all
uncertain and false. They can then go over each belief in turn and
re-adopt only those which they recognize to be true and indubitable.
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