182 ANIMAL-SENTIENT FORCES. [i. 



341. The reason why the free-will movements take place in 

 a given series^ and in no other_, can only be sought in the 

 arbitary and spontaneous production by the mind of the intel- 

 lectual desires and aversions, and no external inducements are 

 necessary thereto_, as in the sentient actions of the sensational 

 desires and aversions, except in so far as the will depends on 

 the sensational faculty (109, 339). 



342. The free-will movements are produced by a special 

 impression of an intellectual desire or aversion in the brain, 

 which acts on the origin of the nerves distributed to the 

 muscles, and is propagated outwards from the brain (164, i). 

 Everything hinders the free-will movement, in spite of the 

 will, which prevents this impression being made or transmitted, 

 or which diverts it from its course to the muscles (164, iii, iv), 

 or renders the muscle unfit to perform its proper function 

 (165, vi). On the other hand, an impression may be made on 

 the origin or trunk of a motor nerve independently of the 

 will, and if it be propagated to the muscle, and the latter be in 

 a fit state to perform its functions, may excite movements, 

 usually voluntary, in spite of the will (162). It is, therefore, 

 erroneous to say, that a movement of the extremities, usually 

 voluntary, must always depend on the will, or that all free-will 

 movements must always take place whenever the mind wills. 

 Daily experience contradicts both propositions, for a natural 

 and incidental hindrance in the body, may prevent a movement 

 that we will, from taking place (see § 165, vi) ; and further, 

 movements that are usually voluntary, may be produced by 

 external sensations, or as nerve actions (183), not only without 

 an act of the will, but in spite of it (162). 



343. The free-will movements have a very important and 

 general influence in the whole animal economy, through the 

 mutual connection of all the forces. Works on physiology 

 may be consulted as to the details {vide Haller^s ' Physiology,^ 

 § 416). 



344. Just as every animal has its predominent instinct and 

 passion (295, 329), so those that possess an understanding and 

 will have their pj'edominant inclination, or, in other words, 

 intellectual desires for that class of conceptions which are most 

 usual with them, because the mind finds the most pleasure 

 therein ; and according to which its voluntary actions are for 



