The essence of sin is self-assertion or self-will, and consequent separation from God. Tauler has, perhaps, a deeper sense of sin than any of his predecessors, and he revives the Augustinian (anti-Pelagian) teaching on the miserable state of fallen humanity. Sensuality and pride, the two chief manifestations of self-will, have invaded the _whole_ of our nature. Pride is a sin of the spirit, and the poison has invaded "even the ground"--the "created ground," that is, as the unity of all the faculties. It will be remembered that the Neoplatonic doctrine was that the spiritual part of our nature can take no defilement. Tauler seems to believe that under one aspect the "created ground" is the transparent medium of the Divine light, but in this sense it is only potentially the light of our whole body. He will not allow the sinless _apex mentis_ to be identified with the personality. Separation from God is the source of all misery. Therein lies the pain of hell. The human soul can never cease to yearn and thirst after God; "and the greatest pain" of the lost "is that this longing can never be satisfied." In the _German Theology_, the necessity of rising above the "I" and "mine" is treated as the great saving truth. "When the creature claimeth for its own anything good, it goeth astray." "The more of self and me, the more of sin and wickedness. Be simply and wholly bereft of self." "So long as a man seeketh his own highest good _because_ it is his, he will never find it. For so long as he doeth this, he seeketh himself, and deemeth that he himself is the highest good." (These last sentences are almost verbally repeated in a sermon by John Smith, the Cambridge Platonist.) The three stages of the mystic's ascent appear in Tauler's sermons. We have first to practise self-control, till all our lower powers are governed by our highest reason. "Jesus cannot speak in the temple of thy soul till those that sold and bought therein are cast out of it." In this stage we must be under strict rule and discipline. "The old man must be subject to the old law, till Christ be born in him of a truth." Of the second stage he says, "Wilt thou with St. John rest on the loving breast of our Lord Jesus Christ, thou must be transformed into His beauteous image by a constant, earnest contemplation thereof." It is possible that God may will to call thee higher still; then let go all forms and images, and suffer Him to work with thee as His instrument. To some the very door of heaven has been opened--"this happens to some with a convulsion of the mind, to others calmly and gradually." "It is not the work of a day nor of a year." "Before it can come to pass, nature must endure many a death, outward and inward."