two are four" which supports the "felt necessity" of believing this truth.
Mr Cairns is so polite as to call my first principle or starting-point, "a barren generality." Considering that, it is wonderful what a large family it has. This is a sort of Irish barrenness, which laughs to scorn the preventive check, and would have driven Malthus to despair. He adds, "out of this truism, even out of the most fertile truth, to evolve all other, is an assumption which philosophy does not warrant, and which experience has hitherto shown to be too great for the human faculties." To which it seems a sufficient answer to say: Prejudge nothing, do not talk idly of what philosophy does or does not warrant, or of what experience has hitherto shown; but grapple with what is now asserted to have been done, and show, if you can, that it has not been done.
The second result of my system is said by Mr Cairns to be this:—
"II. That it denies the separate existence of the material world, while it has only proved that the material world cannot be known without a mind to know it."
Let me explicate the reasoning which Mr Cairns has palmed off upon the public in that article, as mine. It is this: The material world cannot be known without a mind to know it. But what cannot be known without a mind to know it, cannot have a separate existence. Therefore, the material world has no separate existence. This miserable folly is passed off upon the world as my reasoning. Why, it is not only not my reasoning, but I have been at the most particular pains in the Institutes to point out that it is not my reasoning—that it is not reasoning at all (see prop. iv., obs. 11-14). Observe, too, what idiocy Mr Cairns has kindly attributed to me. "I have proved," he says, "that the material world cannot be known without a mind to know it!" If he would point out the passage in the Institutes where this recondite conclusion is reached, the favour would be gratefully acknowledged.
My argument is as follows. The only material world which
