The thesis developed here is that (a) when such departures have occurred in insanity cases, a critical rather than instructive view of jurors has prevailed; (b) this critical view impedes efforts to empirically understand jurors' constructs of insanity and thereby restricts considered legal changes; (c) the Insanity Defense Reform Act of 1984 is illustrative of such narrowly considered changes, and based on empirical findings, this act fails to instruct jurors or produce verdicts different from its predecessors' and (d) based on empirical findings the common sense construals of sane and insane do emerge, complex though they be. Suggestions toward an empirically derived "common law" test of insanity, one that harmonizes legal, psychological, and common sense perspectives are offered. 1 note, 85 references. (Author abstract)