The principle of bivalence is the assertion that every statement is either true or else false. Its legal analog, however, must be formulated relative to particular legal systems and in terms of validity rather than truth. It asserts that every statement of law that can be formulated in the vocabulary of a given legal system is valid (correct) or else invalid (incorrect) in that system. A line of New York cases is traced, beginning with Thomas v. Winchester (1852). This case, which involved a poison mislabeled as a medicine, established an exception to the rule that a manufacturer or supplier is never liable for negligence to a remote purchaser. The court made an exception because a poison is an “imminently dangerous” thing. How far may this exception be applied to other fact-situations? Some subsequent cases are examined, and it is considered whether there is no correct answer in these instances and, more dramatically, whether more than one correct answer is tenable. In either event the legal analog of bivalence would seem to fail.