All soul is immortal. For that which is always in movement is immortal; that which moves something else, and is moved by something else, in ceasing from movement ceases from living. So only that which moves itself, because it does not abandon itself, never stops moving. But it is also source and first principle of movement for the other things which move.
PlatoA man who is good for anything ought not to calculate the chance of living or dying; he ought only to consider whether in doing anything he is doing right or wrong - acting the part of a good man or of a bad.
Plato