Space (Lat. spatium) is a term which, taken in it, most general sense, comprehends whatever is extended and may be measured by the three dimensions, length breadth, and depth. In this sense it is the same with extension. Space, in this large significance, is either occupied by body or it is not. If it be not, but is void of all matter and contains nothing, then it is space in the strictest meaning of the word. This is the sense in which it is commonly used in English philosophical language, and is the same with what is called a vacuum.
Very many theories have been held respecting space a few of which are mentioned below. Zelio of Elea argues against the reality of space, and says, "If all that exists were in a given space, this space must be in another space, and so on ad infinitum." Melissus of Samo, declares that "there exists no empty space, since such a space, if it existed, would be an existing nothing." The Atomists, on the other hand, held to an empty space, arguing
(1) that motion requires a vacuum;
(2) that rarefaction and condensation are impossible without empty intervals of space; and
(3) that organic growth depends on the penetration of nutriment into the vacant spaces of bodies. Aristotle held that; space is limited; the world possesses only a finite extension; outside of it is no place.
The place of anything, he defines, "is the inner surface of the body surrounding it, that surface being conceived as fixed and immovable. As nothing exists outside of the world except God, who is pure thought and not in space, the world naturally cannot be in space, i.e. its place cannot be defined." The Stoics believed that "beyond the world exists an unlimited void." According to Epicurus, "space exists from eternity, and that in the void spaces between the worlds the gods dwell." Arnobius, the African, asserted that God is "the place and space of all things." Space, as containing all things, was by Philo and others identified with the infinite. So the text (Ac 17:28) which says that "in God we live, and move, and have our being" was interpreted to mean that space is an affection or property of the Deity. Eckhart declares that "out of God the creature is a pure nothing; time and space, and the plurality which depends on them, are nothing in themselves." According to Campanella (1568-1639), God produced space (as well as ideas, angels, etc.) "by mingling in increasing measures nonbeing with his pure being. Space is animate, for it dreads a vacuum and craves replenishment." Newton regards space as infinite, the sensorium of the Deity. Leibnitz defines space as "the order of possible coexisting phenomena." Locke has attempted to show that "we acquire the idea of space by sensation, especially by the senses of touch and sight." In the philosophy of Kant, "space and time are mere forms of the sensibility, the form of all external phenomena; and as the sensibility is necessarily anterior in the subject to all real intention, it follows that the form of all these phenomena is in the mind a priori. There can, then, be no question about space or extension but in a human or subjective point of view. The idea of space has no objective validity; it is real only relatively to phenomena, to things, in so far as they appear to us; it is purely ideal in so far as things are taken in themselves and considered independently of the forms of sensibility," Herder says that "space and time are empirical conceptions." Schopenhauer teaches, with Kant, that "space, time, etc., have a purely subjective origin, and are only valid for phenomena, which are merely subjective representations in consciousness. Space and time have the peculiarity that all of their parts stand to each other in a relation, with reference to which each of them is determined and conditioned by another. In space this relation is termed position, in time it is termed sequence." Herbart holds that extension in space involves a contradiction. Extension implies prolongation through numerous different and distinct parts of space, but by such prolongation the one is broken up into the many, while yet the one is to be considered as identical with the many. Trendelenburg seeks to show that space is a product or phase of motion, its, immediate external manifestation. In the philosophy of Thomas Reid (1785), "space and its relations, with the axioms concerning its existence and its relations, are known directly in connection with the senses of touch and sight, but not as objects of these senses." James Mill thus explains infinite space: "We, know no infinite line, but we know a longer and a longer .... In the process, then, by which we conceive the increase of a line the idea of one portion more is continually associated with the preceding length, and to what extent soever it is carried the association of one portion more is equally close and irresistible. This is what we call the idea of infinite extension, and what some people call the necessary idea." According to lord Monboddo, place is space occupied by body. It is different from body as that which contains is different from that which is contained. Space, then, is place potentially; and when it is filled with body, then it is place actually. See Krauth's Fleming, Vocabulary of the Philosophical Sciences, s.v.;. Ueberweg, Hist. of Philosophy (see Index).