Prof. Muni Mahendra Kumar
Modern western philosophy and also modern science, it can be said, began with French philosopher and mathematician René Descartes (1596-1650). His notion of space seems to be based on the doctrine of "chora'' propunded by Plato in his Timeaus. Plato's belief that one characteristic possessed in common by all the fleeting objects of sense-experience is chora, appears to be reflected in Descartes's proposition, that the essence of matter is extension.
"On this proposition he based first some reasoning of a scholastic kind; the relation of extension to material body is, inscholastic language, that of "attribute" to "substance", and since an attribute can have no existence except as the attribute of some substance, it follows that there can be no such thing as extension without matter, or in other words, there cannot be vacuum."[1]
Thus, for Descartes, extension is an adjective, not a substantive; its substantive is matter, and without its substantive it cannot exist. Empty space, to him is as absurd as happiness without a sentiment being who is happy.[2] Thus was deduced what for physicist is the most significant feature of the cartesian system, namely, the assertion that space is a plenum.[3] Descartes has thus not accepted space as an independent reality.
Another French philosopher and contemporary of Descartes, Pierie Gassendi (1592-1655), a priest who held a chair in the College de France, opposed the Cartesian doctrine of space. He thought that space is an existing being, unique in its kind, halfway between body and spirit, and neither substance nor accident.[4] In opposition to the cartesian doctrine of space as a plenum, he defended the conception of atoms moving in the void, which Epicurus (C. 300 B.C.) had adopted from its originators Democritus and Leucippus, differing in size and shape, but not differing in constitution. The importance of Gassendi's views on space is that his opinions on this subject were adopted by Newton (1642-1727), and consequently came to be assumed as fundamental in all the physical investigations of the succeeding two-and-a-half centuries.[5]
Philosophy of Leibnitz (1643-1716), a German philosopher and mathematician and contemporary of Newton, has an important place in the history of Western philosophy. Leibnitz's concepts of space and time are important because of their originality and still more important because the views of Einstein, the renowned scientist of the present century, have a great resemblance with those three hundred years old concepts. Leibnitz has vigorously criticized the Newtonian doctrine of space and time.[footer]6/footer]
Leibnitz, in the last year of his life (1716) expressed his own conviction thus: "I hold space, and also time, to be something purely relative. Space is an order of co-existence as time is an order of successions. Space denotes in terms of possibility an order of things which in so far as they exist together exist at the same time, whatever be their several ways of existing. Whenever we see various things together, we are conscious of this order between things themselves."[7]
Thus, according to Leibnitz, space and time are neither things nor properties of things, but they are an order of things. "Absolute real space and time", Leibnitz maintains, "is an Idolon tribus of English philosophers."[7] Leibnitz denied the existence of any such thing as an absolute space, as he believed it to be a mere order or relation of things, which in itself is indicative of relativity. Also his space is only ideal-a product of mind, for it is a certain order in which the mind conceives the application of relations. Like the space of Descartes, though on somewhat different grounds. Leibnitz's space is also plenum, for it has no existence in the absence of things. To sum up, we can say that Leibnitz's space and time are subjective reality and plenum.
