1. All mystics agree that Ultimate Reality whether It is called Allah, Brahman, Buddha-nature, En-sof, God, or the Tao cannot be grasped by thought or expressed in words. (In fact, the word mystic is related to the word mute, both of which derive from the Greek root mustes, meaning "close-mouthed.")

The Tao which can be named is not the true Tao. Lao Tzu (Taoist)

The Spirit supreme is immeasurable, inapprehensible, beyond conception, never-born, beyond reasoning, beyond thought. Upanishads (Hindu)

Words and sentences are produced by the law of causation and are mutually conditioning they cannot express highest Reality. The Lankavatara Sutra (Buddhist)

That One which is beyond all thought is inconceivable by all thought. Dionysius the Areopagite (Christian)

The gnostics know, but what they know cannot be communicated. It is not in the power of the possessors of this most delightful station...to coin a word which would denote what they know. Ibn 'Arabi (Muslim)