term 'elements,' or 'letters'? For there is no real
resemblance between the relation of letters to a syllable, and of the
terms to a proposition.

Plato, in the spirit of the Megarian philosophy, soon discovers a flaw
in the explanation. For how can we know a compound of which the simple
elements are unknown to us? Can two unknowns make a known? Can a whole
be something different from the parts? The answer of experience is that
they can; for we may know a compound, which we are unable to analyze
into its elements; and all the parts, when united, may be more than all
the parts separated: e.g. the number four, or any other number, is more
than the units which are contained in it; any chemical compound is more
than and different from the simple elements. But ancient philosophy
in this, as in many other instances, proceeding by the path of mental
analysis, was perplexed by doubts which warred against the plainest
facts.

Three attempts to explain the new definition of knowledge still remain
to be considered. They all of them turn on the explanation of logos. The
first account of the meaning of the word is the reflection of thought in
speech--a sort of nominalism 'La science est une langue bien faite.' But
anybody who is not dumb can say what he thinks; therefore mere speech
cannot be knowledge. And yet we may observe, that there is in this
explanation an element of truth which is not recognized by Plato; viz.
that truth and thought are inseparable from language, although mere
expression in words is not truth. The second explanation of logos is the
enumeration of the elementary parts of the complex whole. But this is
only definition accompanied with right opinion, and does not yet attain
to the certainty of knowledge. Plato does not mention the greater
objection, which is, that the enumeration of particulars is endless;
such a definition would be based on no principle, and would not help us
at all in gaining a common idea. The third is the best explanation,--the
possession of a characteristic mark, which seems to answer to the
logical definition by genus and difference. But this, again, is equally
necessary for right opinion; and we have already determined, although
not on very satisfactory grounds, that knowledge must be distinguished
from opinion. A better distinction is drawn between them in the Timaeus.
They might be opposed as philosophy and rhetoric, and as conversant
respectively with necessary and contingent matter.