Yet this Principle, notwithstanding its intuitive certainty, needs to be evoked by reflection from the latency in which it lies concealed, in the confused thought of the unreflecting. It is only gradually, and with the help of reasoning, that the world presented to the senses is distinctly recognised in this its deepest and truest reality. And even when we see that the phenomena _immediately_ presented to our senses need to be realised in percipient experience, in order to be concretely real, we are ready to ask whether there may not be substances _like_ the things so presented, which can exist "without mind," or in a wholly material way (sect. 8). Nay, are there not _some_ of the phenomena immediately presented to our senses which do not need living mind to make them real? It is allowed by Locke and others that all those qualities of matter which are called _secondary_ cannot be wholly material, and that living mind is indispensable for _their_ realisation in nature; but Locke and the rest argue, that this is not so with the qualities which they call _primary_, and which they regard as of the essence of matter. Colours, sounds, tastes, smells are all allowed to be not wholly material; but are not the size, shape, situation, solidity, and motion of bodies qualities that are real without need for the realising agency of any Mind or Spirit in the universe, and which would continue to be what they are now if all Spirit, divine or human, ceased to exist?
The supposition that some of the phenomena of what is called Matter can be real, and yet wholly material, is discussed in sections 9-15, in which it is argued that the things of sense cannot exist really, in _any_ of their manifestations, unless they are brought into reality in some percipient life and experience. It is held impossible that any quality of matter can have the reality which we all attribute to it, unless it is spiritually realised (sect. 15).
But may Matter not be real apart from all its so-called qualities, these being allowed to be not wholly material, because real only within percipient spirit? May not this wholly material Matter be Something that, as it were, exists _behind_ the ideas, phenomena, or qualities that make their appearance to human beings? This question, Berkeley would say, is a meaningless and wholly unpractical one. Material substance that makes and can make no real appearance--unphenomenal or unideal--stripped of all its qualities--is only "another name for abstract Being," and "the abstract idea of Being appeareth to me the most incomprehensible of all other. When I consider the two parts or branches which make up the words _material substance_, I am convinced there is no distinct meaning annexed to them" (sect. 17). Neither Sense nor Reason inform us of the existence of real material substances that exist _abstractly_, or out of all relation to the secondary and primary qualities of which we are percipient when we exercise our senses. By our senses we cannot perceive more than ideas or phenomena, aggregated as individual things that are presented to us: we cannot perceive substances that make no appearance in sense. Then as for reason, unrealised substances, abstracted from living Spirit, human or divine, being altogether meaningless, can in no way explain the concrete realisations of human experience. In short, if there are wholly unphenomenal material substances, it is impossible that we should ever discover them, or have any concern with them, speculative or practical; and if there are not, we should have the same reason to assert that there are which we have now (sect. 20). It is impossible to put any meaning into wholly abstract reality. "To me the words mean either a direct contradiction, or nothing at all" (sect. 24).