, but for the wheat now in the market, the wheat of the
present time: it is concerning this that the attribute of dearness is
predicated; it is this that is in the class of dear things.

_The expression of_ MODALITY _in the Syllogistic Forms_. Propositions
in which the predicate is qualified by an expression of necessity,
contingency, possibility or impossibility [_i.e._, in English by
_must_, _may_, _can_, or _cannot_], were called in Mediaeval Logic
_Modal_ Propositions. "Two and two _must_ make four." "Grubs _may_
become butterflies." "Z _can_ paint." "Y _cannot_ fly."

There are two recognised ways of reducing such propositions to the
form S is P. One is to distinguish between the _Dictum_ and the
_Mode_, the proposition and the qualification of its certainty, and
to treat the _Dictum_ as the Subject and the _Mode_ as the Predicate.
Thus: "That two and two make four is necessary"; "That Y can fly is
impossible".

The other way is to treat the Mode as part of the predicate.
The propriety of this is not obvious in the case of Necessary
propositions, but it is unobjectionable in the case of the other three
modes. Thus: "Grubs are things that have the potentiality of becoming
butterflies"; "Z has the faculty of painting"; "Y has not the faculty
of flying".

The chief risk of error is in determining the quantity of the subject
about which the Contingent or Possible predicate is made. When it is
said that "Victories may be gained by accident," is the predicate made
concerning All victories or Some only? Here we are apt to confuse the
meaning of the contingent assertion with the matter of fact on which
in common belief it rests. It is true only that some victories have
been gained by accident, and it is on this ground that we assert in
the absence of certain knowledge concerning any victory that it
may have been so gained. The latter is the effect of the contingent
assertion: it is made about any victory in the absence of certain
knowledge, that is to say, formally about all.

The history of Modals in Logic is a good illustration of intricate
confusion arising from disregard of a clear traditional definition.
The treatment of them by Aristotle was simple, and had direct
reference to tricks of disputation practised in his time. He specified
four "modes," the four that descended to mediaeval logic, and he
concerned himself chiefly with the import of contradicting these
modals. What is the true contradictory of such pro