This paper is intended to be more modest than even its subtitle "attempt" denotes. The writers feel confident that a key principle, roughly reminding one of the principle of Gray's botany for the diagnosis of plants, is applicable to the diagnosis of nervous diseases. Central in the application of such a key principle is the idea of exclusion of diseases in diagnostic consideration by means of following a certain order. But granting the theoretical virtues of a key principle and of the method of orderly diagnosis by exclusion, we must remain uncertain whether the order adopted is the one best way, in the sense of the efficiency engineer who devised that term.
The attempt to apply a key principle to the differentiation of the major groups of nervous diseases was based on the comparative success of the application of