How is it cowardly if you refuse to engage in debates that are futile? By the same token you can say that Qui-Gon and Obi-Wan were "cowardly" in TPM in trying to kill Maul because they didn't engage in a debate. Actually there are several different definitions of what a coward is. The wikipedia states: "Cowardice is a vice that is conventionally viewed as the corruption of prudence. Cowardice may be considered to be prudence that does not take consequences to their furthest extent. Cowardice is not fear, but rather a submission to vice that uses fear as a pretext. Here is an example of virtuous fear: we all fear to dive head-first into a swimming pool the depth of which we do not know. An example of cowardice would be to refuse to testify against a crime lord, merely because one might risk death." Fear is one of the most basic instincts in any evolved living being. It warns you of dangers and thus it has since ever been a prerequisite in the evolutionary struggle to survive. Someone who has no fear is not brave but stupid. The difference between cowardice and bravery is what the wikipedia calls the use of "prudence", which is the use of caution in the face of danger and considerate judgement of whether it is appropriate and worthwhile to face that danger. To run even though it's neccessary to face the danger is cowardice. Had he avoided revealing himself to Anakin, had he fled when Anakin ignited his lightsaber, or had he evaded the confrontation with Mace, all confrontations useful for his goal, that would have been cowardice. When he faced Yoda, he had already achieved his goal of becoming Emperor, and the only "merit" of this fight was risking what he had achieved. The Jedi order had been practically defeated by then and there wasn't anything worthwile he could gain from this fight.