Is it not, rather, ignorance to know all else without knowing oneself, the knower? As soon as one knows the Self, which is the substratum of knowledge and ignorance; then knowledge and ignorance perish.
That alone is true Knowledge which is neither knowledge nor ignorance. What is known is not true Knowledge. Since the Self shines with nothing else to know or to make known, Self alone is Knowledge. It is not a void.
The Self, which is Knowledge, is the only Reality. Knowledge of multiplicity is false knowledge. This false knowledge, which is really ignorance, cannot exist apart from the Self, which is Knowledge-Reality. The variety of gold ornaments is unreal, since none of them can exist without the gold of which they are all made.
(Source: Forty Verses on Reality by Sri Ramana Maharshi, translated by Arthur Osborne.)