Page:Ferrier's Works Volume 3 "Philosophical Remains" (1883 ed.).djvu/327

a knowledge of something existing in things, over and above our mere knowledge of them, is not one whit less our knowledge, and is not one whit more their existence, than the other more subjective knowledge designated by the word mere. Our knowledge of extension and figure is just as little these real qualities themselves, as our affection of colour is objective colour itself. Just as little we say, and just as much. You (we suppose ourselves addressing an imaginary antagonist), you hold that our knowledge of the secondary qualities is not these qualities themselves; but we ask you, Is, then, our knowledge of the primary qualities these qualifies themselves? This you will scarcely maintain; but perhaps you will say, Take away the affection of colour, and the colour no longer exists; and we retort upon you, Take away the knowledge of extension, and the extension no longer exists. This you will peremptorily deny, and we deny it just as peremptorily; but why do both of us deny it? Just because both of us have subreptitiously restored the knowledge of extension in denying that extension itself would be annihilated. The knowledge of extension is extension, and extension is the knowledge of extension. Perhaps, in continuation, you will say, we have our own ideas, the secondary qualities are in truth our own ideas; but that besides these we have an idea of something existing externally to us which is not an idea, and that this something forms the aggregate of the primary quali-