2012 Reprint of 1951 Edition. Exact facsimile of the original edition, not reproduced with Optical Recognition Software. Kenneth Arrow's monograph "Social Choice and Individual Values" and a theorem within it created modern social choice theory, a rigorous melding of social ethics and voting theory with an economic flavor. The work culminated in what Arrow called the "General Possibility Theorem," better known thereafter as Arrow's (impossibility) theorem. The theorem states that, absent restrictions on either individual preferences or neutrality of the constitution to feasible alternatives, there exists no social choice rule that satisfies a set of plausible requirements. The result generalizes the voting paradox, which shows that majority voting may fail to yield a stable outcome.