Mysticism is the experience that life is not logic, that life is poetry; that life is not syllogism, that life is a song. Mysticism is the declaration that life can never really be known; it is essentially unknowable.
Science divides existence into two categories: the known and the unknown. The known was unknown one day; it has become known. The unknown is unknown today; tomorrow, or the day after tomorrow, it will also become known. Science believes that sooner or later a point of understanding will arrive when there will be only one category: the known, all will have been known. The unknown is slowly being reduced to the known.
Mysticism is the declaration that life consists of three categories: one, the known; another, the unknown; and the third, and the most important, is the unknowable – which has not been known and which will never be known. And that is the essential core of it all.
That unknowable can be experienced but not known. It cannot be reduced to knowledge, although your heart can sing its song. You can dance it, you can live it, you can be full and overflowing with it – you can be possessed by it – but you will not be able to know it.