The soul is like a ship…

The soul is like a ship: sometimes it is sunk by a mighty swell from without, sometimes from within because the bilge is overflowing. So too are we sometimes lost through sinful practices on the outside, sometimes defiled by logismoi [evil thoughts] within. So we must watch out for the attacks of the spirits from outside and drain off the impurities of the logismoi within.
–Saint Synkletike (a Desert Mother) (d. 350)