When I ask «is matter infinite or not» putting this as a question of reality I err. For matter is the external sum of our sensations and possesses neither of these characteristics.

As a sensation, as a thing perceived, it is necessarily finite, suo genere, in its own kind. It is not finite in opposition to infinite (in the usual sense of the word). It is limited, so that it may be perceived. The sum of sensations must be something to give a general sensation; and by something is meant, if not exactly something finite, necessarily something definite, finite in this sense.