INTROD.] VOLITION. SENSATION. 25 



and animals. In the former it is cryptogamic, or phanerogamic; 

 in the latter, non-sexual, or sexual. In the phanerogamic and 

 sexual, the junction of two kinds of matter furnished by the 

 parents is necessary to the development of fertile ova. In the 

 cryptogamic and non- sexual generation, the new individual is de- 

 veloped by a separation of particles from the body of the parent, 

 by which the new formation is nourished until it has been so far 

 matured as to be capable of an independent existence. 



The functions, hitherto enumerated, may be called organic, as 

 being common to all organized beings ; but there are others which, 

 as being peculiar to, and characteristic of, animals, may be appro- 

 priately designated animal functions. 



The prominent characteristic of animals is the enjoyment of 

 Volition or Will, which implies necessarily the possession of Con- 

 sciousness. Our knowledge of the share which consciousness and 

 the will have in the production of certain phenomena of animal life, 

 is derived from the experience which each person has of his own 

 movements, and a comparison of them with the actions of inferior 

 animals. We are conscious that, by a certain effort of the mind, 

 we can excite our muscles to action ; and when we see precisely 

 similar acts performed by the lower creatures, with all the marks 

 of a purpose, it is fair to infer that the same process takes place 

 in them as in ourselves. Moreover, we learn by experience, that 

 injury or disease of the nerves, which are distributed to our muscles, 

 destroys the power of accomplishing a certain act, but does not 

 affect the desire or the wish to perform it : arid experiments tell us 

 that the division of the nerves of a limb in a lower animal destroys 

 its power over that member ; while its ineffectual struggles to move 

 the limb obviously indicate that the will itself is not affected by the 

 bodily injury, though its powers are limited by it. 



Again, certain external agents are capable of affecting the mind, 

 through certain organs, thus giving rise to Sensations. Light, sound, 

 odour, the sapid qualities of bodies, their various mechanical pro- 

 perties, hardness, softness, &c., are respectively capable of producing 

 corresponding affections of the mind, which experience leads us to 

 associate with their exciting causes, and which may be agreeable, 

 and produce pleasure, or the reverse, and give rise to pain. 



In a similar way to that by which we learn that the will stimu- 

 lates our muscles through the nerves, we can ascertain that the 

 nerves are the channels through which our sensations also are ex- 

 cited. " Certain states of our bodily organs are directly followed 

 by certain states or affections of our mind ; certain states or affec- 



