First duty (Christianity)

To see and accept the boundaries of the human mind without rebellion and to work within these limitations without ceasing is where the first duty lies. The mind can only perceive appearances and not the essences of things. It can not perceive all appearances but only those of matter. It can not even see the appearances of matter but only the relationships between them. These relationships are not real and independent of the human mind but its creation. These relationships are not the only one possible, but the most convenient for his needs.

The first duty in the preparation for the spiritual exercises of Nikos Kazantzakis.