Part I outlines the basic elements of self-defense and explains how at least two of the elements of self-defense -- the necessity and proportionality requirements -- imply a reasonable act requirement that is separate and apart from a reasonable belief requirement. Part II explores two evolving concepts in self-defense doctrine. It first discusses the meaning of reasonableness, suggesting that the current bipolar conception of reasonableness should be replaced with a conception of reasonableness that recognizes various gradations of objectivity. Part II then discusses evolving formulations of the defense of self-defense, including theories that focus exclusively on the defendant's beliefs, theories that focus exclusively on whether the defendant was correct about the justifying circumstances, and theories that focus on both the defendant's beliefs and whether the defendant was correct. Part II concludes by suggesting a new formulation that focuses on both the reasonableness of the defendant's beliefs and the reasonableness of the defendant's acts, without requiring the defendant to be correct about the existence of the justifying circumstances. Part III elaborates on this new dual requirement theory of self-defense, concluding by discussing possible objections to the proposed reform of the Federal Code. 143 footnotes and appended chart of gradations of objectivity along a spectrum of reasonableness