re beginning to analyze, to classify, to define,
to ask what is the nature of knowledge, opinion, sensation. Still less
could they be content with the description which Achilles gives in Homer
of the man whom his soul hates--

os chi eteron men keuthe eni phresin, allo de eipe.

For their difficulty was not a practical but a metaphysical one; and
their conception of falsehood was really impaired and weakened by a
metaphysical illusion.

The strength of the illusion seems to lie in the alternative: If we once
admit the existence of Being and Not-being, as two spheres which exclude
each other, no Being or reality can be ascribed to Not-being, and
therefore not to falsehood, which is the image or expression of
Not-being. Falsehood is wholly false; and to speak of true falsehood, as
Theaetetus does (Theaet.), is a contradiction in terms. The fallacy
to us is ridiculous and transparent,--no better than those which
Plato satirizes in the Euthydemus. It is a confusion of falsehood and
negation, from which Plato himself is not entirely free. Instead of
saying, 'This is not in accordance with facts,' 'This is proved by
experience to be false,' and from such examples forming a general notion
of falsehood, the mind of the Greek thinker was lost in the mazes of the
Eleatic philosophy. And the greater importance which Plato attributes
to this fallacy, compared with others, is due to the influence which
the Eleatic philosophy exerted over him. He sees clearly to a certain
extent; but he has not yet attained a complete mastery over the ideas of
his predecessors--they are still ends to him, and not mere instruments
of thought. They are too rough-hewn to be harmonized in a single
structure, and may be compared to rocks which project or overhang in
some ancient city's walls. There are many such imperfect syncretisms or
eclecticisms in the history of philosophy. A modern philosopher, though
emancipated from scholastic notions of essence or substance, might
still be seriously affected by the abstract idea of necessity; or though
accustomed, like Bacon, to criticize abstract notions, might not extend
his criticism to the syllogism.

The saying or thinking the thing that is not, would be the popular
definition of falsehood or error. If we were met by the Sophist's
objection, the reply would probably be an appeal to experience. Ten
thousands, as Homer would say (mala murioi), tell falsehoods and
fall into errors. And this is Plato's reply