It is plain, of course, that any proof of this depends upon the validity of the doctrine of a priori cognition; only by our proved possession of such cognition can there be any evidence that we are self-active realities. It is in this reference noteworthy, therefore, that Lange, as defender of agnosticism, sees he cannot afford to admit the theory upon which alone cognition strictly a priori can be established.
— GEORGE HOLMES HOWISON