That which is necessary or at least conducive to the actual operation of a cause
Condition (Lat. conditio, from condo, to bring, or put, together; sometimes, on account of a somewhat similar derivative from condicere, confused with this) is that which is necessary or at least conducive to the actual operation of a cause, though in itself, with respect to the particular effect of which it is the condition, possessing in no sense the nature of causality. Thus the notion of a condition is not that of a real principle such as actually gives existence to the effect produced (which is the case in the notion of cause); but rather of a circumstance, or set of circumstances, in which the cause readily acts, or in which alone it can act. Thus a sufficient light is a condition of my writing, though it in no sense is, as I myself am, the cause of the act of writing. The writing is the effect of the writer, and not of the light by which it was performed. A condition is also to be distinguished from an occasion, which latter imports no more than an event, or thing, by reason of the presence of which any other event, or thing, takes place—as, for example, the passage of the king in state is the occasion of my removing my hat—while the action, or actual operation, of the cause is absolutely dependent upon the presence of this particular one, or of some condition. Condition is, for this reason, distinguished, with respect to the operation of any particular cause, (I) as the condition sine qua non, or condition without the presence of which this cause is wholly inoperative, and (2) as the condition simply such—when some one of several possible ones is necessary to the actual operation of the cause. To the former class belong such conditions as can be supplied by no others, such as, for example, that of the combustion of wood. A fire will not burn wood unless applied to it. The application of the fire to the wood is said to be a condition sine qua non of the burning of the wood by the fire. A condition may further be considered in one of two different forms, either as preparing, disposing, or applying the causality of a cause towards its exercise in the production of an effect, or as removing some obstacle that hinders the action of the cause. This latter form of condition is sometimes known as the causa removens prohibens. The blinds of a room must be drawn up in order that the sunlight may enter and illuminate the objects in it. It is to be noted that this is really a condition, and not a cause, of the event considered. The illumination of the objects in the room is the effect of the sunlight entering it. This same distinction appears in the "necessary", or "sufficient" conditions, much employed in mathematical science. A sufficient condition is one in which, when the antecedent is present, it is always followed by the consequent. A necessary condition is one in which the consequent never exists unless this particular antecedent be given.
Some modern systems of philosophy regard condition in the sense of what in the Scholastic view would be called accidental modification. Thus Kant up-holds the assertion that time and space condition, or are the conditions of, our experience, as a priori forms. In this sense also, Hegel makes the conditioned entity equivalent to the finite entity; as it would indeed also be considered in Scholastic thought. That which has accidents, or is conditioned in the sense of limitations or definition, is necessarily, as contingent, in sharp distinction to the absolute. John Stuart Mill would have the framework, or complete setting in which anything exists accounted as its conditions; and all the necessary antecedents, or conditions, the cause of the thing. Thus it would be conditioned by its complex relationships—again an accidental modification in the Scholastic sense. We consequently find, in modern philosophical usage generally, and especially since Hamilton's theory of the Unconditioned was formulated, that the "conditioned" and the "unconditioned" are used as equivalents of the "necessary" and "contingent" of the Schoolmen, in the sense that the "necessary" entity is conceived of as absolute of all determination other than its own aseity, while all "contingent" entity is defined and limited by a composition in which one of the factors is potentiality. Hamilton's philosophy of the Unconditioned works out curiously in the department of ontology. His views were first given to the world in the form of an article in the Edinburgh Review (October, 1829), in which he criticized the philosophy of Cousin with regard to the knowledge of the Absolute. Victor Cousin maintained that we possess an immediate knowledge of the Unconditioned, Absolute, or Infinite in consciousness. According to Hamilton, the Unconditioned is either the unconditionally limited or the unconditionally unlimited. In either case the Unconditioned is unthinkable. For all human knowledge is relative, in that, "of existence, absolutely and in itself, we know nothing" (Met., Lect. viii). As a consequence of this doctrine of the relativity of knowledge, it follows that we are incapable of knowing that which is unconditioned by relativity. "The mind can conceive, and consequently can know only the limited, and the conditionally limited". "Conditional limitation", he says again (Logic, Lect. v) "is the fundamental law of the possibility of thought." Hence, while the Unconditioned may exist, we cannot know it by experience, intuition, or reasoning. Hamilton undertakes to explain his doctrine by the illustration of the whole and the part. It is impossible to conceive a whole to which addition may not be made, a part from which something may not be taken away. Hence the two extreme unconditionates are such, that neither can be conceived as possible, but one of them must be admitted as necessary. Of this, the Unconditioned, we have no notion either negative or positive. It is not an object of thought. From such considerations it follows that we cannot conclude either as to the existence or non-existence of the Absolute. On the other hand, while our knowledge is of the limited, related, and finite, our belief may go out to that which has none of these characteristics. Though we cannot know, we may believe—and, by reason of a supernatural revelation, if such be given, must believe—in the existence of the Unconditioned as above and beyond all that which is conceivable by us. Mill very carefully examines Hamilton's use of the word inconceivable, and finds that it is applied in three senses, in one of which all that is inexplicable, including the first principles, is held to be inconceivable. The same doctrine was advanced, in a slightly modified form, by Dean Mansel, in the Hampton Lecture of 1858. Whatever knowledge we are capable of acquiring of the Unconditioned is negative. As we can rationally, therefore, form no positive notion or concept of God, our reason must be helped and supplemented by our faith in revelation. Both Mansel's and Hamilton's expositions of the doctrine of relativity are in reality assertions of rational, or philosophical, agnosticism.
Thus, while professing to be theists, writers of this stamp are not properly to be accounted such in the strictly philosophical sense. The rational agnosticism that lies at the base of their theistic system, necessitating, as it does, an appeal to faith and rev-elation, vitiates it as a philosophy. The thesis advanced by them may, however, be criticized and amended in the following manner. It is true that the entire content of the Universe must be regarded, in comparison with its Creator, as limited or conditioned. It does not therefore follow that no rational inference can be drawn from the conditioned to the Absolute. On the contrary, the nerve of the theistic inference, tacitly, if not expressly, presupposed in all forms of the theistic argument, lies in the Thomistic distinction between the Necessary and the possible (or contingent). The existence of contingent beings, limited or conditioned things, postulates the existence of the Necessary Being, the one Unlimited and Unconditioned Thing. The argument in its developed form may be seen in the article Theism. But it may be here pointed out that the inference from the contingent to the Necessary—necessitated, as it is, by the normal psychological action of the discursive reason—presupposes certain principles which are not always kept clearly in view. The Scholastic synthesis recognizes the reality of the contingent. It asserts that the human intelligence can rise above the phenomena of sense-perception to the actual substance that provides a basis and offers a rational explanation, at the same time psychological and onto-logical, of and for these. And it is in the changes and alterations of "substance" (see Hylomorphism) that it perceives the essential contingency of all created things. From this perception it rises, by a strictly argumentative process, to the assertion of the Necessary or Unconditioned—and this with no appeal either to revelation or to faith. The knowledge of the Unconditioned thus reached is of two kinds: firstly, that the Unconditioned is, and that its existence is necessarily to be inferred from the existence of the possible or contingent (conditioned); secondly, that, as Unconditioned, or Necessary, the conceptions that we possess of it are to be found principally by the way of the negation of imperfections. Thus the Unconditioned, with regard to time, is Eternal; with regard to space, Unlimited, Infinite, Omnipresent; with regard to power, Omnipotent; and so on through the categories, removing the imperfections and asserting the plenitude of perfection. The argument may be found stated in the "Summa Theologica" of St. Thomas (I, Q. ii, a. 3), where it is given as the third way of knowing Utrum Deus sit.