CH. III.] SUBORDINATE SENTIENT ACTIONS. 115 



the mechanical machines, from a movement produced in the 

 latter, by means of material external sensation sent from the 

 brain, they can thereby excite new external sensations (31), 

 and these can develope sentient actions, either in the same 

 mechanical machines by means of the same nerves, or their 

 branches ; or in other machines to which they are distributed, 

 or to which their cerebral impression is transmitted (188). 

 Sentient actions from external sensations of this second class 

 are subordinate, or secondary, as to their origin, and if we 

 would avoid many errors in explaining the phenomena of the 

 animal economy, they must be carefully distinguished from 

 those which arise directly from external sensations. Pain in 

 a muscle excites cramp of the muscle, its direct sentient action. 

 But this cramp causes also a violent pain, from which con- 

 vulsions result, involving many other muscles. These con- 

 vulsions are subordinate sentient actions of the primary pain. 

 A poison excites a burning sensation in the stomach and bowels, 

 in consequence of which they writhe, and are spasmodically 

 contracted. These are the primary sentient actions of the ex- 

 ternal sensations of burning from the poison. But the writhing 

 and spasmodic contraction cause new pain (colic, spasms of the 

 stomach), whereby the circulation of the blood in the abdomen, 

 and the digestion and transmission forwards of the food, are 

 hindered, the bowels constipated, dysuria induced, and the legs 

 paralysed (212). These are the subordinate or secondary actions 

 of the sensation of burning excited by the poison, and the 

 direct sentient actions of the gastric spasm or colic. It is 

 obvious, that when these subordinate actions excite new sen- 

 sations, new sentient actions may result which are again sub- 

 ordinate. Thus, therefore, a single external sensation can, by 

 means of its subordinate and continuous direct sentient actions 

 excite most, if not all, the mechanical machines of the body to 

 movement; spasmodic diseases, from titillation, &c., present 

 the most frequent examples of this kind. It must therefore 

 be remembered, (and it will be subsequently advanced in treating 

 of the actions arising from other sentient forces,) that the 

 subordinate external sensations of the mind constitute, when 

 combined with the primary, a compound external sensa- 

 tion (an entire or complete [conception] external sensation, 

 — Baumgarten^s ' Metaphysics,' § 378), which consists of the 



