d
on the truth of another; these propositions are distinguished from
categorical propositions, which simply state a fact, as being "composed
of two categorical propositions united by a conjunction," e.g. if A is
B, C is D. The second statement (the "consequent") is restricted or
qualified by the first (the "antecedent"). By some logicians these
propositions are classified as (1) Hypothetical, and (2) Disjunctive,
and their function in syllogistic reasoning gives rise to the following
classification of conditional arguments:--(a) Constructive hypothetical
syllogism (_modus ponens_, "affirmative mood"): If A is B, C is D; but A
is B; therefore C is D. (b) Destructive hypothetical syllogism (_modus
tollens_, mood which "removes," i.e. the consequent): if A is B, C is D;
but C is not D; therefore A is not B. In (a) the antecedent must be
affirmed, in (b) the consequent must be denied; otherwise the arguments
become fallacious. A second class of conditional arguments are
disjunctive syllogisms consisting of (c) the _modus ponendo tollens_: A
is either B or C; but A is B; therefore C is not D; and (d) _modus
tollendo ponens_: A is either B or C; A is not B; therefore A is C. A
more complicated conditional argument is the dilemma (q.v.).[1]

The limiting or restrictive significance of "condition" has led to its
use in metaphysical theory in contradistinction to the conception of
absolute being, the _aseitas_ of the Schoolmen. Thus all finite things
exist in certain relations not only to all other things but also to
thought; in other words, all finite existence is "conditioned." Hence
Sir Wm. Hamilton speaks of the "philosophy of the unconditioned," i.e.
of thought in distinction to things which are determined by thought in
relation to other things. An analogous distinction is made (cf. H. W. B.
Joseph, _Introduction to Logic_, pp. 380 foll.) between the so-called
universal laws of nature and conditional principles, which, though they
are regarded as having the force of law, are yet dependent or
derivative, i.e. cannot be treated as universal truths. Such principles
hold good under present conditions, but other conditions might be
imagined under which they would be invalid; they hold good only as
corollaries from the laws of nature under existing conditions.

(2) _In Law_, condition in its general sense is a restraint annexed to a
thing, so that by the non-performance the party to it shall receive
prejudice and loss, and by th