ad infinitum.  And, moreover, you will perhaps object that as each cognition is of an essentially illuminating nature like a lamp, the assumption of a further cognition is uncalled for; for as they are both equally illuminating the one cannot give light to the other.—­But both these objections are unfounded.  As the idea only is apprehended, and there is consequently no necessity to assume something to apprehend the Self which witnesses the idea (is conscious of the idea), there results no regressus ad infinitum.  And the witnessing Self and the idea are of an essentially different nature, and may therefore stand to each other in the relation of knowing subject and object known.  The existence of the witnessing Self is self-proved and cannot therefore be denied.—­Moreover, if you maintain that the idea, lamplike, manifests itself without standing in need of a further principle to illuminate it, you maintain thereby that ideas exist which are not apprehended by any of the means of knowledge, and which are without a knowing being; which is no better than to assert that a thousand lamps burning inside some impenetrable mass of rocks manifest themselves.  And if you should maintain that thereby we admit your doctrine, since it follows from what we have said that the idea itself implies consciousness; we reply that, as observation shows, the lamp in order to become manifest requires some other intellectual agent furnished with instruments such as the eye, and that therefore the idea also, as equally being a thing to be illuminated, becomes manifest only through an ulterior intelligent principle.  And if you finally object that we, when advancing the witnessing Self as self-proved, merely express in other words the Bauddha tenet that the idea is self-manifested, we refute you by remarking that your ideas have the attributes of originating, passing away, being manifold, and so on (while our Self is one and permanent).—­We thus have proved that an idea, like a lamp, requires an ulterior intelligent principle to render it manifest.

29.  And on account of their difference of nature (the ideas of the waking state) are not like those of a dream.

We now apply ourselves to the refutation of the averment made by the Bauddha, that the ideas of posts, and so on, of which we are conscious in the waking state, may arise in the absence of external objects, just as the ideas of a dream, both being ideas alike.—­The two sets of ideas, we maintain, cannot be treated on the same footing, on account of the difference of their character.  They differ as follows.—­The things of which we are conscious in a dream are negated by our waking consciousness.  ’I wrongly thought that I had a meeting with a great man; no such meeting took place, but my mind was dulled by slumber, and so the false idea arose.’  In an analogous manner the things of which we are conscious when under the influence of a magic illusion, and the like, are negated by our ordinary consciousness.