I. Space.
Subjective View.—What is space? Is it a mere idea, a mere conception of the mind, or has it reality? This is a question which has much perplexed philosophers. Kant and his school regard both time and space as merely subjective, mere conceptions or forms which the mind imposes upon outward things, having no reality, save as conceptions, or laws of thought.
Opposite View.—On the other hand, if we make space a reality, and not a mere conception, what is it, and where is it? Not matter, and yet real, a something which exists, distinct from matter, and yet not mind. Pressed with these difficulties, some distinguished and acute writers have resolved time and space into qualities of the one infinite and absolute Being, the divine mind. Such was the view of Clarke and Newton, a view favored also by a recent French writer of some note—C. H. Bernard, Professor of Philosophy in the Lycée Bonaparte.
A middle Ground.—These must be regarded as, on either hand, extreme views. But is there a middle ground possible or conceivable? Let us see. What, then, is the simple idea of space? What mean we by that word?
Idea of Space.—When we contemplate any material object, any existence of which the senses can take cognizance, we are cognizant of it as extended, i. e., occupying space, nor can we possibly conceive of it as otherwise. The idea of space, then, is involved in the very idea of extended substance, or material existence, given along with it, impossible to be separated from it. We may regard it, therefore, as the condition or postulate of being, considered as material existence, possessing extension, etc. The idea of it is essential to the idea of matter, the reality of it to the reality of matter; for if there were no space, there could be no extension in space, and, without extension, no matter.
Not a mere Conception.—Is space, then, a mere conception of the mind, merely subjective? Unquestionably not. It is not, indeed, a substance or entity, it has no being. It is not matter, for it is, itself, the condition of matter; it is not spirit, for then it were intelligent. It is not an existence, then, strictly speaking, not a thing created, nor is it in the power of deity either to create or to annihilate it, for creation and annihilation relate only to existence. And yet space is a reality, and not a mere conception of the mind. For, if so, then were there no longer any mind to conceive it, there would be no longer any space; if no mind to think, then no thought. Were the whole race of intelligent beings, then, to be blotted out of existence, and all things else to remain as now, space would be gone, while, yet, matter would exist, extension—worlds moving on as before. Extension in what, motion in what? Not in space, for that is no longer extant; defunct, rather, with the last mind whose expiring torch went out in the gloom of night. Unless we make matter, then, to be also a mere conception of the mind, space is not so. If the one is real, the other is. If one is a mere conception, so is the other; and to this result the school of Kant actually come. Matter, itself, is a subjective phenomenon, a mode of mind, or, rather, if it be any thing more, we have no means of knowing it to be so.
If, on the contrary, as we hold, matter exists, and is an object of immediate perception by the senses, then there is such a thing as space also, the condition of its existence, a reality, though not an entity, the idea of it given along with that of matter, the reality of it implied in the reality of matter. Matter presupposes it, depends on it as its sine quâ non. It depends on nothing. Were there no matter, there would be none the less space, but only space unoccupied. In that case, the idea of space might never occur to any mind, but the reality would exist just as now. Were all matter and all mind to be blotted out of being, space would still be what it is now.
The Idea, how awakened—How come we by our Idea of Space?—Sense gives us our first knowledge of matter, as extended, etc., and so furnishes the occasion on which the idea of space is first awakened in the mind. In this sense, and no other, does it originate in sensation or experience. It is a simple idea, logically prior to experience, because the very notion of matter presupposes space; yet, chronologically, as regards the matter of development in the mind, subsequent to experience and cognizance of matter.
II. Time.
Idea and Definition.—What we have said of space will enable us better to understand what is the nature of that analogous and kindred conception of the mind, in itself so simple, yet so difficult of definition and explanation—Time. The remarks already made, respecting space, will almost equally apply to this subject also.