As nouns the difference between truth and altruism
is that
truth is the state or quality of being true to someone or something while
altruism is regard for others, both natural and moral without regard for oneself; devotion to the interests of others; brotherly kindness; selflessness;
contrasted with egoism or selfishness .
As a verb truth
is (obsolete|transitive) to assert as true; to declare, to speak truthfully.