desires to know. We are supposed, first, to know the ideas on their own account as mental states or mental entities, and subsequently, by a process of conscious inference, to refer them to real causes and archetypes. If knowledge at any stage did terminate thus in the ideas themselves, it is difficult to see either what considerations could suggest to us the step beyond their charmed circle or on what grounds it could be justified. This is in fact the point of the idealistic and sceptical criticism which Berkeley and Hume brought to bear upon Locke's hypothetical Realism. Berkeley, as Green puts it, tries to avoid Locke's inconsistencies by dropping the reference to transcendent real objects altogether: for idea of an object he deliberately substitutes idea simply. To him the ideas are the objects, sensible things are clusters or collections of ideas – actual and possible perceptions of intelligent beings. "The table I write on exists, that is, I see and feel it; and if I were out of my study, I should say it existed – meaning thereby that, if I was in my study, I might perceive it or that some other spirit actually does perceive it." In his recurring phrase, the being of things "is to be perceived or known," or, as he puts it even more strikingly, "the object and the sensation are the same thing." "An idea can be like nothing but an idea" and the supposition of independent originals of our ideas is gratuitous. "If there were external bodies, it is impossible we should ever come to know it." The supposition of such bodies is, in short, not only "groundless and absurd," but "is the very root of scepticism; for so long as men thought that real things subsisted without the mind, and that their knowledge was only so far forth real as it was conformable to real things, it follows that they could not be certain that they had any real knowledge at all. For how can it be known that the things which are perceived are conformable to those which are not perceived, or exist without the mind?"[1] As Hume clinched the matter afterwards: The mind has never anything present to it but the perceptions, and cannot possibly reach any experience of their connection with objects. Hence Berkeley proceeds, "All this
- ↑ Principles of Human Knowledge, Section 86.