We sought, therefore, to formulate a classification in which the various groups should be so defined as to obviate the interference of personal equation in the work of applying it, hoping thus to achieve greater accuracy. In this we can lay claim to only partial success; for, in the first place, having satisfactorily defined a number of groups, we found it necessary in the end to provide a special group for unclassified reactions, into which falls more than one-third of the total number of individual reactions; and, in the second place, in at least two of our groups the play of personal equation has not been entirely eliminated, so that there is still a possibility of error to the extent of five per cent of individual reactions, which means approximately one per cent of the total number of reactions. We have found, however, that in spite of these shortcomings the classification here proposed is more serviceable than others which, though more comprehensive, are at the same time lacking in definiteness. Our classification consists of the following classes, groups and subdivisions: I. _Common reactions._ 1. Specific reactions. 2. Non-specific reactions. II. _Doubtful reactions._ III. _Individual reactions._ 1. Normal reactions. 2. Pathological reactions: A. Derivatives of stimulus words. B. Partial dissociation: (a) Non-specific reactions. (b) Sound reactions: a. Words. b. Neologisms. (c) Word complements. (d) Particles of speech. C. Complete dissociation: (a) Perseveration: a. Association to preceding stimulus. b. Association to preceding reaction. c. Repetition of preceding stimulus. d. Repetition of previous stimulus. e. Repetition of preceding reaction. f. Repetition of previous reaction. g. Reaction repeated five times (stereotypy). (b) Neologisms without sound relation. 3. Unclassified. § 3. NON-SPECIFIC REACTIONS; DOUBTFUL REACTIONS. *Non-specific Reactions.*--It has already been intimated that common reactions are in the vast majority of instances to be regarded as normal. From amongst them, however, a fairly definite group can be separated out which seems to possess some pathological significance, namely, the group which we have termed non-specific. In this group are placed words which are so widely applicable as to serve as more or less appropriate reactions to almost any of our stimulus words. That such reactions are in value inferior to the remaining group of common reactions, which we have termed, in contradistinction, _specific reactions_, is perhaps sufficiently obvious; we shall speak later, however, of their occurrence in both normal and insane cases.