In concluding this series of examples culled outside my own special domain, I will quote the linguistic hypothesis of Finck,[189] where we also see the duality in question. The structure of language, according to Finck, presents two principal types: in one the subject is generally conceived as active: "I see him," "I strike him down;" in the other the subject experiences and feels, and it is the object which acts: "He appears to me," "He succumbs to me." The first type clearly shews the libido as going out of the subject,--this is a centrifugal movement; the second as coming out of the object,--this movement is centripetal. We meet with this latter introverted type especially in the primitive languages of the Esquimaux. In the domain of psychiatry also these two types have been described by Otto Gross,[190] who distinguishes two forms of mental debility: the one a diffuse and shallow consciousness, the other a concentrated and deep consciousness. The first is characterised by weakness of the consecutive function, the second by its excessive reinforcement. Gross has recognised that the consecutive function is in intimate relation with affectivity, from which we might infer that he is dealing once more with our two psychological types. The relation he establishes between maniac depressive insanity and the state of diffuse or extended and shallow mental disease shows that the latter represents the extroverted type; and the relation between the psychology of the paranoiac and repressed mentality, indicates the identity of the former with the introverted type. After the foregoing considerations no one will be astonished to find that in the domain of psychoanalysis we also have to reckon with the existence of these two psychological types. On the one side we meet with a theory which is essentially reductive, pluralist, causal and sensualist; this is Freud's standpoint. This theory limits itself rigidly to empirical facts, and traces back complexes to their antecedents and their elemental factors. It regards the psychological life as being only an effect, a reaction to the environment, and accords the greatest _rôle_ and the largest place to sensation. On the other side we have the diametrically opposed theory of Adler[191] which is an entirely philosophical and finalistic one. In it phenomena are not reducible to earlier and very primitive factors, but are conceived as "arrangements," the outcome of intentions and of ends of an extremely complex nature. It is no longer the view of causality but of finality which dominates researches: the history of the patient and the concrete influences of the environment are of much less importance than the dominating principles, the "fictions directrices," of the individual. It is not essential for him to depend upon the object, and to find in it his fill of subjective enjoyment, but to protect his own individuality and to guarantee it against the hostile influences of the environment.