Die "anthropologia transcendentalis". Das Rätsel eines kantischen Paradoxons

In a reflection forming part of Kant’s Handschriftlicher Nachlass that has been traced back by Adickes to the years between 1776 and 1778 there occurs a phrase which occurs nowhere else in the entire body of Kant’s works: “transcendental anthropology” (anthropologia transcendentalis, no. 903 in AA XV, 395).In this passage Kant places in close relation with one another the “common sense” represented by the “point of view of all other human beings” and the self-knowledge of intellect and reason. The “second eye” and the necessity for a plurality of viewpoints represent “humanity” and the capacity to “judge with affability”. Kant defines all this as “transcendental anthropology” and he does so, significantly (assuming that Adickes’s dating of this reflection is correct) a few years before the publication of the first edition of the Critique of Pure Reason and a few years after taking his decision to lecture on anthropology as an academic subject in its own right (1772/73). What, then, exactly does Kant mean when he speaks of an anthropologia transcendentalis? Is it possible to reconstruct the genesis of this expression and to find sources for it?