It is with the last of these only that logic is concerned.

176. The proposition, therefore, corresponds to the Indicative and
Potential, or Conditional, sentences of grammar. For it must be borne
in mind that logic recognises no difference between a statement of
fact and a supposition. 'It may rain to-morrow' is as much a
proposition as 'It is raining now.'

177. Leaving the grammatical aspect of the proposition, we must now
consider it from the purely logical point of view.

178. A proposition is a judgement expressed in words; and a
judgement is a direct comparison between two concepts.

179. The same thing may be expressed more briefly by saying that a
proposition is a direct comparison between two terms.

180. We say 'direct comparison,' because the syllogism also may be
described as a comparison between two terms: but in the syllogism the
two terms are compared indirectly, or by means of a third term.

181. A proposition may be analysed into two terms and a Copula,
which is nothing more than the sign of agreement or disagreement
between them.

182. The two terms are called the Subject and the Predicate ( 58).

183. The Subject is that of which something is stated.