You should also learn to distinguish the impassioned thoughts that promote
every sin. The thoughts that encompass all evil are eight in number: those
of gluttony, unchastity, avarice, anger, dejection, listlessness,
self-esteem and pride. It does not lie within our power to decide whether
or not these eight thoughts are going to arise and disturb us. But to dwell
on them or not to dwell on them, to excite the passions or not to excite
them, does lie within our power.”
St. John of Damascus.