Paul Cooijmans published a proof of the existence of absolute truth in one sentence.
http://members.chello.nl/p.cooijmans/essay/truth.htm
Now, evil. Evil is what causes suffering. Trouble is we have different opinions on who the bad guy is. Even in quite obvious cases!
The ultimate decider of good and evil is of course me. While I half jest there, that is the philosophy that almost all people live by.
Lava