Page:Ferrier's Works Volume 1 - Institutes of Metaphysic (1875 ed.).djvu/179

RhPROP. V.———— of psychology it runs into a palpable contradiction—into the contradiction to which expression is given in this fifth counter-proposition, which declares that certain qualities of matter can be known, without the me or subject being known along with them. How this contradiction comes about will be obvious from the following considerations.

8. This distinction has been employed by psychology in refutation of what it conceives to be idealism. Idealism, according to psychology, is founded on a refusal to recognise the primary qualities of matter as clearly distinguishable from the secondary. It is supposed to confound the two classes under a common category, or rather to reduce the primary qualities to the same character and condition as the secondary—to resolve extension, figure, and solidity, no less than heat, and colour, and sound, into mere modifications of the sentient subject. It is supposed to maintain that the primary qualities are just as obscure and occult as the secondary; that in dealing with the material universe we are cognisant, not of the qualities of external objects, but only of certain changes in our own sentient condition, and thus idealism is supposed to have succeeded either in abolishing or in rendering doubtful the absolute existence of material things;—because, if the primary qualities stand