179. Of this result he himself shows no suspicion. He professes to be able, without violence to his doctrine, to accept the sciences as they stand, except so far as they rest upon the needless and unmeaning assumptions (as he reckoned them) of _pure_ space and its infinite divisibility. The truth seems to be that--at any rate in the state of mind represented his earlier treatises--he was only able to work on the lines which Locke had laid. It did not occur to him to treat the primary qualities as relations constituted by thought, because Locke had not done so. Locke having treated them as external to the mind, Berkeley does so likewise, and for that reason feels that they must be got rid of. The mode of riddance, again, was virtually determined for him by Locke. Locke having admitted that they copied themselves in feelings, the untenable element in this supposition had only to be dropped and they became feelings simply. It is thus only so far as space is supposed to exist after a mode of which, according to Locke himself, sense could take no copy--_i.e._ as exclusive not merely of all colour but of all body, and as infinitely divisible--that Berkeley becomes aware of its incompatibility with his doctrine. Pure space, or ‘vacuum,’ to him means space that can not be touched--a tangible extension that is not tangible--and is therefore a contradiction in terms. The notion that, though not touched, it might be seen, he excludes, [1] apparently for the same reason which prevents him from allowing _visible_ extension to be space at all; the reason, namely, that there is no ‘outness’ or relation of externality between the parts of such extension. The fact that there can be no such relation between the successive feelings which alone, according to him, constitute ‘tangible extension,’ he did not see to be equally fatal to the latter being in any true sense space. In other words, he did not see that the test of reduction to feeling, by which he disposed of the _vacuum_, disposed of space altogether. If he had, he would have understood that space and body were intelligible relations, which can be thought of apart from the feelings which through them become the world that we know, since it is they that are the conditions of these feelings becoming a knowledge, not the feelings that are the condition of the relations being known. Whether they can be thought of apart from each other--whether the simple relation of externality between parts of a whole can be thought of without the parts being considered as solid--is of course a further question, and one which Berkeley cannot be said properly to discuss at all, since the abstraction of space from body to him meant its abstraction from feelings of touch. The answer to it ceases to be difficult as soon as the question is properly stated. [1] ‘Principles of Human Knowledge,’ sec. 116. Berkeley disposes of space for fear of limiting God.