activity but by the impulse which its own absolute existence excites in matter ([Greek: hos eromenon], [Greek: ou kinoumenon]). The Aristotelian conception of form was nominally, though perhaps in most cases unintelligently, adopted by the Scholastics, to whom, however, its origin in the observation of the physical universe was an entirely foreign idea. The most remarkable adaptation is probably that of Aquinas, who distinguished the spiritual world with its "subsistent forms" (_formae separatae_) from the material with its "inherent forms" which exist only in combination with matter. Bacon, returning to the physical standpoint, maintained that all true research must be devoted to the discovery of the real nature or essence of things. His induction searches for the true "form" of light, heat and so forth, analysing the external "form" given in perception into simpler "forms" and their "differences." Thus he would collect all possible instances of hot things, and discover that which is present in all, excluding all those qualities which belong accidentally to one or more of the examples investigated: the "form" of heat is the residuum common to all. Kant transferred the term from the objective to the subjective sphere. All perception is necessarily conditioned by pure "forms of sensibility," i.e. space and time: whatever is perceived is perceived as having spacial and temporal relations (see SPACE AND TIME; KANT). These forms are not obtained by abstraction from sensible data, nor are they strictly speaking innate: they are obtained "by the very action of the mind from the co-ordination of its sensation."