 According to Frege, there are exactly two truth values, the True and the False. This opinion appears to be rather restrictive, and one may ask whether it is really indispensable for the concept of a truth value. One should observe that in elaborating this conception, Frege assumed specific requirements of his system of the Begriffsschrift, especially the principle of bivalence taken as a metatheoretical principle, viz. that there exist only two distinct logical values. On the object-language level this principle finds its expression in the famous classical laws of excluded middle and non-contradiction. The further development of modern logic, however, has clearly demonstrated that classical logic is only one particular theory (although maybe a very distinctive one) among the vast variety of logical systems. In fact, the Fregean ontological interpretation of truth values depicts logical principles as a kind of ontological postulations, and as such they may well be modified or even abandoned. For example, by giving up the principle of bivalence, one is naturally led to the idea of postulating many truth values.