Amalek is the essence of chutzpa, of completely irrational challenge to truth. There are challenges to the truth that are based on rational argument. There are evasions that arise from subjective motives and desires. But then there is "Amalek," who neutralizes the most compelling evidence and chills the most inspiring experience with nothing more than his cynicism and audacity.
There is only one way to defeat Amalek: to remember. Because his challenge is not rational, it cannot be rationally refuted; because it immune to feeling, it cannot be repelled by a rousing of emotion. To counteract Amalek's poison, one must call forth the souls reserves of supra-rational faith, instilled within it when it was first formed as a spark of the divine essence--a faith which, when remembered, can meet his every moral challenge.
(The Chassidic Masters)