positions as, "It
is possible to be" ([Greek: dynaton einai]), "It admits of being"
([Greek: endechetai einai]), "It must be" ([Greek: anankaion einai]),
"It is impossible to be" ([Greek: adynaton einai])? What is implied in
saying "No" to such propositions put interrogatively? "Is it possible
for Socrates to fly?" "No." Does this mean that it is not possible for
Socrates to fly, or that it is possible for Socrates not to fly?

A disputant who had trapped a respondent into admitting that it is
possible for Socrates not to fly, might have pushed the concession
farther in some such way as this: "Is it possible for Socrates not to
walk?" "Certainly." "Is it possible for him to walk?" "Yes." "When you
say that it is possible for a man to do anything do you not believe
that it is possible for him to do it?" "Yes." "But you have admitted
that it is possible for Socrates not to fly?"

It was in view of such perplexities as these that Aristotle set forth
the true contradictories of his four Modals. We may laugh at such
quibbles now and wonder that a grave logician should have thought them
worth guarding against. But historically this is the origin of the
Modals of Formal Logic, and to divert the names of them to signify
other distinctions than those between modes of qualifying the
certainty of a statement is to introduce confusion.

Thus we find "Alexander was a great general," given as an example of
a Contingent Modal, on the ground that though as a matter of fact
Alexander was so he might have been otherwise. It was not _necessary_
that Alexander should be a great general: therefore the proposition
is _contingent_. Now the distinction between Necessary truth and
Contingent truth may be important philosophically: but it is merely
confusing to call the character of propositions as one or the other by
the name of Modality. The original Modality is a mode of expression:
to apply the name to this character is to shift its meaning.

A more simple and obviously unwarrantable departure from tradition
is to extend the name Modality to any grammatical qualification of
a single verb in common speech. On this understanding "Alexander
conquered Darius" is given by Hamilton as a _Pure_ proposition, and
"Alexander conquered Darius honourably" as a _Modal_. This is a merely
grammatical distinction, a distinction in the mode of composing the
predicate term in common speech. In logical tradition Modality is a
mode of qualifying the certain