300 MORBID SENSATIONS. 



more general in others. We know, that light impresses the retina ; 

 aerial undulations the acoustic nerve, &c. ; but, in the internal sen- 

 sations or sentiments, as some of the French writers term them, the 

 source of the irritation is in some modified action of the part itself, in 

 the very tissue of the organ, and hence the result is said to be organic. 

 In the internal sensation of hunger, for example, the impression is en- 

 gendered in the organ, how, we know not, is thence conveyed to 

 the brain, and the sensation is not effected until the latter has acted. 

 The same may be said of all the internal sensations. They differ, in 

 other respects, also, from the external. Whilst the latter may be 

 entirely passive, or rendered active by volition, without either action 

 being the cause of particular pleasure or inconvenience, the former are 

 little influenced by volition. Constituting the wants the instinctive 

 desires which impel to acts, that are necessary for the preservation 

 and full developement of the individual and of the species, such in- 

 dependence is of course essential. On many of them, however, habit 

 or accustomed volition has a certain degree of influence; and they can 

 unquestionably be augmented or moderated by licentious indulgence 

 or restraint. The influence of habit is exemplified by the regularity 

 with which the appetite returns at stated intervals ; and by the differ- 

 ence between that of the gourmand and of the temperate individual. 

 It is most strikingly evidenced, however, in its influence over the 

 moral wants ; which may even spring up from social indulgence, and 

 hence are not instinctive or organic. We are every day compelled 

 to witness the striking difference between the individual who practises 

 restraint upon his wants, and the libertine, who, like the animals sur- 

 rounding him, gives unbridled sway to his natural and acquired appe- 

 tites. 



All the internal sensations, when satisfied or responded to in mode- 

 ration, communicate a feeling of pleasure; but if resisted, pain re- 

 sults. If hunger be prolonged, there is a general feeling of uneasi- 

 ness, which rapidly abates after food is received into the stomach ; but 

 if satiety be produced, uneasiness follows ; and this applies to all the 

 appetites or wants. The special internal sensations will engage us, 

 when the functions to which they belong fall under consideration. 

 Like the external sensations, they must, of course, administer to the 

 intellect, to an extent which will be seen hereafter. Their influence 

 and nature were entirely neglected until of comparatively late years, 

 when attention was directed to them chiefly through the labours of 

 MM. Cabanis 1 and of Destutt-Tracy ; 2 and they now form subjects for 

 interesting speculation, with the metaphysician more especially. 



The morbid sensations belong more particularly to pathology ; a 

 brief notice of them will consequently be all that is necessary here. 

 They are comprised under the term pain. In its enlarged significa- 

 tion, this word, as is well known, means every uneasy or disagreeable 

 sensation or moral affection; thus including sadness, anger, terror, 

 as well as the painful impressions felt in the extremities or trunks of 



1 Rapport du Physique et du Morale de 1'Homme, torn, ii., Paris, 1802. 

 3 Siemens d'Ideologie, 2de edit., Paris, 1804. 



