79. HABITS AND DISPOSITIONS.—Every created being is subject to change, capable of development or retrogression, endowed with a natural tendency towards some end which it can reach by a natural process of activity, and which constitutes for it, when attained, its full and final perfection (66). Through this process of change it acquires accidental modes of being which help it or hinder it, dispose it or indispose it, in the exercise of its natural activities, and therefore also in the concrete perfection of its nature as tending towards its natural end. Such an accidental mode of being is acquired by a series of transient actions and experiences, _actiones et passiones_: after these have passed away it remains, and not merely as a state or condition resulting from the changes wrought in the subject by these experiences, but as a _disposition_ towards easier repetition of such experiences. Moreover, it may be not a mere transient disposition, but something stable and permanent, not easily removed or annulled, a _dispositio difficile mobilis_. And just as it is essentially indicative of past actions whereby it was acquired, so, too, the very _raison d’être_ of its actuality is to dispose its subject for further and future changes, for operations and effects which are not yet actual but only potential in this subject. Such an accidental mode of being is what Aristotle called ἕξις, and the scholastics _habitus_. With Aristotle, they define _habit_ as a _more or less stable disposition whereby a subject is well or ill disposed in itself or in relation to other things_: _Habitus dicitur dispositio difficile mobilis secundum quam bene vel male disponitur subjectum aut secundum se aut in ordine ad aliud_.(331) The difference between a _habit_ (ἕξις) and a simple _disposition_ (διάθεσις) is that the former is by nature a more or less _stable_ quality while the latter is unstable and transient. Moreover, the facilities acquired by repeated action of the organs or members of men or animals, and the particular “set” acquired by certain tools or instruments from continued use, are more properly called _dispositions_ than _habits_: they are not habits in the strict sense, though they are often called habits in the ordinary and looser usage of common speech. A little reflection will show that _the only proper subjects of natural habits in the strict sense are the spiritual faculties of an intelligent and free agent_.