DISPOSITION disposifio, from dis i,om to dispose, from dis-, apart ± !tonere. to loll ). The hypothesis of mental dispositions has been used ill psychology to bring facts into an intereonnected and coherent system. It is obvious that the conditions of many mental processes are not themselves direetly available to introspection. 1Vhen, e.g. a name is remem bered. it is not always possible to point to the immediate conscious antecedents of the memory. Various hypotheses have been put forward to supply the missing links in the sequence of con scious processes. (tile hypothesis says that the mind has a 'faculty' of remembering (see tti TV) : another, that (lie absent terms are to be explained as physiological factors• which are not themselves accompanied by 'Mt wltieh int rodin•e conseitm• processes; a third hypothesis refers the matter to the 'stibeonseiou•' i.e. to a lower stratum of eonseimisnesq, which and, finally. en lierenee is brought into mental facts by an hy pothesis posits 'mental' or tpsyehical positions: Ito in has spoken of 'the permanent product; stored up in the mental organization' as 'stores in reserve,' the fruits of experience which may he conceived as lying outside con sciousness and yet as affecting mental processes. Such a conception is based upon the fact that past experiences scent continually to color our present thought-. emotions, perceptions, and ac tions. 1 hear a familiar voice, and immediately the face of a f•iend—a- 1 last saw him, perhaps —come- before my mind. Evidently, if I had had no previous knowledge of the individual. the sound would not have 'aroused' the visual image of his face. One may say, in this and similar case, that the previous experience left a 'persistent trace' which serves to revive the image.
The difficulty of the hypothesis lies in its in ability to give any descriptive account of the conditions of consciousness which it exist. If one means by 'psychical dispositions' a host of ready-made sensations, ideas, emotions. etc., which are not in consciousness, but which nevertheless exit, one is surely juggling with terms; for consciousness is involved in the very notion of these processes. But if the disposition is neither mental nor material, it can only be an unknown condition which we may call s. For this is sometimes substituted the 'physiological disposition,' which may be considered a'- a ten dency to functionate. dependent upon the mo lecular condition in which a previous function has left the brain. (See MEmonv.) A physical condition for mental processes is more tangible than a psychical disposition. since it may be deduced from the known laws of neural opera tion. (Sec Bony AND MIND.) A common in stance of 'physiological' or 'functional disposi tion' is furnished. e.g. by the law of neural habit known a= the 'law of co-excitation' of different parts of the brain. (See ASSOCIATION OF IDEAS.) The theory is sometimes rejected on the ground that very little is known in detail con cerning the physiologieal processes underlying •onseiousness. But we are at least abandoning a theory which works fairly well for a bare hypothesis, when we desert 'physiological' for 'psychical disposition.' Consult : Stout, .lnafyt fraf Mond( n, I S9I ) ; t. (Mind :kw der physioloyisehrn Psychologie (Leipzig. 1893) ; Ba in, The Senses and the Intellect (Lon don, 18681.