5. Thus this phrase,--that space is a _form_ belonging to our perceptive power,--may be employed to express that we cannot perceive objects as in space, without an operation of the mind as well as of the senses--without active as well as passive faculties. This phrase, however, {94} is not necessary to the exposition of our doctrines. Whether we call the conception of space a Condition of perception, a Form of perception, or an Idea, or by any other term, it is something originally inherent in the mind perceiving, and not in the objects perceived. And it is because the apprehension of all objects is thus subjected to certain mental conditions, forms or ideas, that our knowledge involves certain inviolable relations and necessary truths. The principles of such truths, so far as they regard space, are derived from the idea of space, and we must endeavour to exhibit such principles in their general form. But before we do this, we may notice some of the conditions which belong, not to our Ideas in general, but to this Idea of Space in particular. {{95}} CHAPTER III. OF SOME PECULIARITIES OF THE IDEA OF SPACE. 1. SOME of the Ideas which we shall have to examine involve conceptions of certain relations of objects, as the idea of Cause and of Likeness; and may appear to be suggested by experience, enabling us to _abstract_ this general relation from particular cases. But it will be seen that Space is not such a general conception of a relation. For we do not speak of _Spaces_ as we speak of Causes and Likenesses, but of Space. And when we speak of _spaces_, we understand by the expression, parts of one and the same identical everywhere-extended Space. We conceive a universal Space; which is not made up of these partial spaces as its component parts, for it would remain if these were taken away; and these cannot be conceived without presupposing absolute space. Absolute Space is essentially one; and the complication which exists in it, and the conception of various spaces, depends merely upon boundaries. Space must, therefore, be, as we have said, not a general conception abstracted from particulars, but a universal mode of representation, altogether independent of experience. 2. Space is infinite. We represent it to ourselves as an infinitely great magnitude. Such an idea as that of Likeness or Cause, is, no doubt, found in an infinite number of particular cases, and so far includes these cases. But these ideas do not include an infinite number of cases as parts of an infinite whole. When we say that all bodies and partial spaces exist _in_ infinite space, we use an expression which is not applied in the same sense to any cases except those of Space and Time. {96}