C.D. Broad on the ordinary understanding of material objects
These are his words below:
It seems to me that the plain man means by a ‘solid body’ or a ‘bit of matter’ something which has all the following characteristics:
(1) It is literally extended. It is bounded by a closed surface and has an outside and a front.
(2) It is literally pervaded throughout its volume and over its surface with certain extensible qualities, e.g., colours, temperature, roughness or smoothness, and so on.
(3) It is a centre from which there emanate certain sensible 'atmospheres', which form a kind of aura about it, e.g., a characteristic field of sound in the case of a tolling bell or a waterfall, a characteristic field of odour in the case of an apple, a field of sensible warmth in the case of a radiator, and so on.
(4) Some of the qualities mentioned under headings (2) and (3) are revealed by some of our senses and others by others. But the very same part of the same body, e.g., the upper face of a certain coin, has at the same time qualities proper to various senses, e.g., colour, temperature, and textural qualities. It has temperature and texture when one is looking at it and not touching it and therefore is sensibly aware only of its colour; and it has colour when one is touching it and not looking at it and therefore is sensibly aware only of its temperature and its texture. Moreover, it has temperature, when one is only looking at it, in precisely the same sense in which it has temperature when one is feeling it; and when one is only touching it it has colour in precisely the same sense in which it has colour when one is looking at it. Lastly, it may have extensible qualities which none of our senses are fitted to reveal to us.
(5) Beside having extensible qualities, which it may present to us sensibly, a bit of matter has certain causal or dispositional properties active or passive. Among these may be mentioned inertial mass, impenetrability, greater or less elasticity and so on.
(6) The same person can perceive the same part or different parts of the same bit of matter on various occasions by means of the same sense or different senses.
(7) Different persons can perceive the same part or different parts of the same bit of matter, by means of the same sense or different senses, on the same occasion.
(8) A bit of matter can exist, and change or remain unaltered, and act upon or be acted upon by other bits of matter, at times when no one is perceiving it. None of its extensible qualities or its powers is altered or abolished or reinstated by its becoming or ceasing to be perceived.
I do not say that all or any of these common sense beliefs are true. But I do say that, unless there be particulars which answer to all these eight conditions, then there are no 'bodies' or 'material things' in the plain straightforward sense of these phrases.
Broad, C.D. 1954. Berkeley’s Denial of Material Substance. Philosophical Review 63: 155-181.