There is also a type that prevents mere absence without precluding combination, such as the non-existence of the conditioned matter together with the existence of its condition. By “condition” we mean here that whose absence entails the absence of the ruling, whether this is known through Revelation or through reason—purification, for instance, is a condition for the validity of prayer, and being alive is a condition for possessing knowledge. This is not the “condition” spoken of by the grammarians, namely the conditional clause introduced by in and its sisters, for in essence that functions as a cause for the occurrence of the apodosis. The word “condition,” then, is applied to both senses only homonymously.

Whoever claims that the term “condition” falls into all three logical divisions has erred, for the absence of the conditioned and the presence of the condition can indeed coincide; the presence of the condition does not necessarily entail the presence of the conditioned. What cannot obtain is the simultaneous absence of both, for if the condition were lacking while the conditioned existed, the condition would be absent and the conditioned present—a state of affairs that is impossible, like saying, “He drowned without water,” “His prayer was valid without ablution,” or “Stoning became obligatory without fornication.” One must rather say: “Either he was in water, or he did not drown; either he was in a state of purification, or his prayer is not valid; either he was a fornicator, or stoning is not permissible.”

Likewise, if someone were to assert, “There is in existence neither a Necessary Being nor a contingent being, neither something eternal nor something originated,” we reply, “Existence must contain either a Necessary or a contingent being, either something eternal or something originated.” These two alternatives can neither coexist nor can they both be absent.

Again, if it is said, “A being is either self-subsistent, like a body, or dependent upon something else, like an accident,” these two cannot both be absent, though they may coexist. Thus, any pair of predicates of which existence is never devoid, while their coexistence is possible—or of which a given class of beings is never devoid, while their coexistence remains possible—falls under this heading.

An illustrative example is the statement: “An heir in his own right inherits either by a fixed share or by agnatic succession.” The two may unite in a single person—such as a husband who is also a paternal cousin or a freedman—so that he inherits both by a fixed share and by agnation.

Hence, the connected conditional pertains to mutual entailment, whereas the disjunctive conditional belongs to the second category, as in the case of contraries and contradictories. This latter form, the form of division that constitutes the disjunctive conditional, is