X.—This letter is one of the important symbols in the Occult philosophy. As a numeral X stands, in mathematics, for the unknown quantity; in occult numerals, for the perfect number 10; when placed horizontally, thus χ, it means 1,000; the same with a dash over it χ for 10,000; and by itself, in occult symbolism, it is Plato’s logos (man as a microcosm) decussated in space in the form of the letter X. The "X," or cross within the circle, has moreover a still clearer significance in Eastern occult philosophy: it IS MAN within his own spherical envelope.

Xenophilus. A Pythagorean adept and philosopher, credited by Lucian (de Macrob.), Pliny and others with having lived to his 170th year, preserving all his faculties to the last. He wrote on music and was surnamed the “ Musician”.

Xisusthrus (Gr.). The Chaldean Noah, on the Assyrian tablets, who is thus described in the history of the ten kings by Berosus, according to Alexander Polyhistor: “After the death of (the ninth) Ardates, his son Xisusthrus reigned eighteen sari. In his time happened a great deluge.” Warned by his deity in a vision of the forthcoming cataclysm, Xisusthrus was ordered by that deity to build an ark, to convey into it his relations, together with all the different animals, bird etc., and trust himself to the rising waters. Obeying the divine admonition, Xisusthrus is shown to do precisely what Noah did many thousand years after him. He sent out birds from the vessel which returned to him again; then a few days after he sent them again, and they returned with their feet coated with mud; but the third time they came back to him no more. Stranded on a high mountain of Armenia, Xisusthrus descends and builds an altar to the gods. Here only, comes a divergence between the polytheistic and monotheistic legends. Xisusthrus, having worshipped and rendered thanks to the gods for his salvation, disappeared, and his companions “saw him no more ”. The story informs us that on account of his great piety Xisusthrus and his family were translated to live with the gods, as he himself told the survivors. For though his body was gone, his voice was heard in the air, which, after apprising them of the occurrence, admonished them to return to Babylon, and pay due regard to virtue, religion, and the gods. This is more meritorious than to plant vines, get drunk on the juice of the grape, and curse one’s own son.