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INSTITUTES OF METAPHYSIC.
PROP. IV.————
afford a presumption in favour of the possibility of some kind of idealism.
A preliminary question prejudged by materialist and by idealist.8. Both the materialist and the idealist have tacitly prejudged an important preliminary question in their discussions respecting the existence of matter. The question is this—Is there, or is there not, any necessary and invincible law of knowledge and of reason which prevents matter per se from being known? The materialist, prejudging this question in the negative, silently decides that there is nothing in the nature of intelligence, or in the constitution and essence of knowledge, to prevent matter per se from being known. Holding, therefore, the knowledge of matter per se to be possible, and surrounded by the glories of a wonderful creation, he very naturally concludes that this knowledge is actual; and holding this knowledge to be actual, he cannot but conclude that matter per se exists. The inference from knowledge to existence is always legitimate. It is not surprising, therefore, that he should be bewildered and irritated by the speculations of those who have called in question the existence of matter per se. But the idealist also has his grounds of justification. He has silently decided this preliminary question in the affirmative. He has seen that in the very nature of reason, in the very constitution of knowledge, there is a necessary and insuperable law which renders any apprehension of matter
