One of clear thinking’s biggest opponents is the ego. This is when an argument, stance, or opinion is supported not by evidence, but by pride, the need to be right, and the desire to avoid shame and embarrassment. Ego keeps us deaf and blind if we allow it to. It serves a purpose, but very quickly becomes detrimental to your evaluation of the world, as it has the power to warp reality around you. The most prominent defense mechanisms we use are rationalization and plain old denial.