according to the recommendation in a previous page, substitute means for is. We then have—
Dragon is a word meaning a thing which breathes flame:
Dragon is a word meaning a serpent:
From which the conclusion is,
Some word or words which mean a serpent, also mean a thing which breathes flame:
where the conclusion (as well as the premises) is true, and is the only
kind of conclusion which can ever follow from a definition, namely, a
proposition relating to the meaning of words.
There is still another shape into which we may transform this syllogism. We may suppose the middle term to be the designation neither of a thing nor of a name, but of an idea. We then have--
The idea of a dragon is an idea of a thing which breathes
flame:
The idea of a dragon is an idea of a serpent:
Therefore, there is an idea of a serpent, which is an idea of
a thing breathing flame.
Here the conclusion is true, and also the premises; but the premises are
not definitions. They are propositions affirming that an idea existing in
the mind, includes certain ideal elements. The truth of the conclusion
follows from the existence of the psychological phenomenon called the idea
of a dragon; and therefore still from the tacit assumption of a matter of
fact.(45)
When, as in this last syllogism, the conclusion is a proposition respecting an idea, the assumption on which it depends may be merely that of the existence of an idea. But when the conclusion is a proposition concerning a Thing, the postulate involved in the definition which stands as the apparent premise, is the existence of a thing conformable to the definition, and not merely of an idea conformable to it. This assumption of real existence we always convey the impression that we intend to make, when we profess to define any name which is already known to be a name of really existing objects. On this account it is, that the assumption was not necessarily implied in the definition of a dragon, while there was no doubt of its being included in the definition of a circle.
