Logical positivists describe certain classes of propositions as analytic or synthetic. Their position would be unassailable if they left the matter at that. Unfortunately they add a rider to the effect that all propositions are one or the other. Pseudo–propositions, being neither one nor the other, are described as nonsense. The above rider itself appears to fall into neither class and an immediate objection may be made to the positivist's standpoint on the ground that it commits him to nonsense by his own definition.