innate knowledge of the basic principles of morality.
Christian Mysticism. the essence of the soul that unites with God.

Origin of synderesis

1350–1400; Middle English < Medieval Latin syndērēsis, syntērēsis < Greek syntḗrēsis a guarding, equivalent to syntērē-, variant stem of syntēreîn to guard closely (syn- syn- + tēreîn to guard) + -sis -sis Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019