The shared doctrine concerns the soul on the path toward union with the Divine. God, being unreachably transcendent, the soul's only approach is to renounce everything but God. Thereby the soul enters a desolation in which he (or she) lives only for God, yet the desolation may become too severe, causing the soul to despair, so that the merciful Deity grants him (or her) inspiration, followed by a phase of elation; afterwards the soul returns to the way through desolation in order to move closer to God. The doctrine shared teaches that the soul passing through these alternating states of "night" (contraction, due to despair) and "day" (inspired expansion) may relinquish the "charismata" of God's inspiring favors, i.e., the "day", so as to pass more quickly beyond the difficult rhythm of "night" and "day". Thereafter the soul finds repose, wherein to enter the transforming union. Asín analyses the technical vocabulary used by the sadilis and by San Juan de la Cruz in order to further establish the connection.