The mystical writers are, in some sense, philosophers. They are trying to understand the world as it is. But they are generally concerned with "knowledge" only to the extent that it leads to what they deem to be "salvation." The mystics are sometimes contrasted with the great Greek philosophers – the pure philosophers are concerned with only the head, while the mystics are concerned with the liberation of the heart and soul.

In Mysticism: East and West, Rudolph Otto compares the lives and thought of two representative mystics – Meister Eckhart of the West and Sankara of the East. In his chapter Not Metaphysics but a Doctrine of Salvation, Otto discusses these two mystics in comparison to philosophers:

"Sankara is usually regarded as the greatest philosopher of India, and Meister Eckhart in the history of philosophy as the creator of an original philosophical system. Yet both are at bottom alike in that they are not so much philosophers as theologians. They are indeed metaphysicians, but not in the sense of the metaphysics of Aristotle or of the philosophical schools. Their impelling interest is not 'science' as a theoretical explanation of the world...Neither of them is concerned for 'knowledge' out of curiosity to explain the world, but each is impelled by a longing for 'salvation.' ...

The 'Being' of which they speak is to be a 'salvation.' That that Being is one, without a second, that it is undivided, without apposition or predicate, without "How" or fashion, these are not merely metaphysical facts but at the same time 'saving' actualities. That the soul is eternally one with the Eternal is not a scientifically interesting statement, but is that fact upon which the salvation of the soul depends."