We evolved to lie to ourselves because it makes us better at lying to
others. Read Wright's THE MORAL ANIMAL.

People like Gandhi or Gates will use any excuse that works to gain social
power (the actual content of their phlisophy is irrelevant). Why? Because
gaining social power tended to increase fitness in the past.

Here are some other folks who got it right:

"In the first place, I put forth a general inclination of all mankind a
perpetual and restless desire of power after power, that ceaseth only in
death." -- Thomas Hobbes

"The first thing a man will do for his ideals is lie." -- Joseph Schumpeter,
1942

"Wherever men hold unequal power in society, they will strive to maintain
it. They will use whatever means are convenient to that end and will seek to
justify them by the most plausible arguments they are able to devise." --
Reinhold Neibuhr

"In fact, telling primates (human or otherwise) that their reasoning
architectures evolved in large part to solve problems of dominance is a
little like telling fish that their gills evolved in large part to solve the
problem of oxygen intake from water." -- Denise Dellarosa Cummins

Jay