d imagination, nor to the new world of
reflection and reason. Plato attempts to clear up this darkness. In
his accustomed manner he passes from the lower to the higher, without
omitting the intermediate stages. This appears to be the reason why he
seeks for the definition of knowledge first in the sphere of opinion.
Hereafter we shall find that something more than opinion is required.

False opinion is explained by Plato at first as a confusion of mind and
sense, which arises when the impression on the mind does not correspond
to the impression made on the senses. It is obvious that this
explanation (supposing the distinction between impressions on the mind
and impressions on the senses to be admitted) does not account for all
forms of error; and Plato has excluded himself from the consideration of
the greater number, by designedly omitting the intermediate processes
of learning and forgetting; nor does he include fallacies in the use of
language or erroneous inferences. But he is struck by one possibility
of error, which is not covered by his theory, viz. errors in arithmetic.
For in numbers and calculation there is no combination of thought and
sense, and yet errors may often happen. Hence he is led to discard the
explanation which might nevertheless have been supposed to hold good
(for anything which he says to the contrary) as a rationale of error, in
the case of facts derived from sense.

Another attempt is made to explain false opinion by assigning to error
a sort of positive existence. But error or ignorance is essentially
negative--a not-knowing; if we knew an error, we should be no longer in
error. We may veil our difficulty under figures of speech, but these,
although telling arguments with the multitude, can never be the real
foundation of a system of psychology. Only they lead us to dwell upon
mental phenomena which if expressed in an abstract form would not be
realized by us at all. The figure of the mind receiving impressions is
one of those images which have rooted themselves for ever in language.
It may or may not be a 'gracious aid' to thought; but it cannot be
got rid of. The other figure of the enclosure is also remarkable as
affording the first hint of universal all-pervading ideas,--a notion
further carried out in the Sophist. This is implied in the birds, some
in flocks, some solitary, which fly about anywhere and everywhere. Plato
discards both figures, as not really solving the question which to