1815.) Intellectual Functions of Man and Animals. 29 
the vital or nutritive system, which Haller inaccurately excludes 
ftom its influence. The motions of the vital, are, however, not less 
important than those of the locomotive, system. 
he term volition, however, may be still applied to the function 
of this organ, whether voluntary or involuntary action be jits result, 
~ because the impulse of the cerebellum.on which they both depend 
is one and the same, and the involuntarity is a modification of that 
impulse or of its effects produced only by ganglia on certain fibrils 
of the cerebellic nerves. This extended meaning of the word 
volition is perfectly analogous to that of the term sensation; for 
though sensation does not exist separately, except in those animals 
which have no sensorium commune,—though, in man, it is inse- 
parable from perception, yet still is the simple term sensation em- 
ployed. An improved nomenclature, however, or an extension of 
the very admirable one of Dr. Barclay, would perhaps give us new 
terms in both cases. 
I have now said, in opposition to the statement of Halier, that 
the cerebrum sends neither sensation nor motion to any part external 
to the encephalic cavity ; and, as Dr. Leach says, I have “ neglected 
to take any notice of the cerebrum,’”’ and seems to demand what 
use I assign to it, I may “ assure him ” that there still remain very 
important uses for it to serve; and as the Doctor, not having sub- 
mitted them to any ‘‘ recent examination,” is perhaps less familiar 
with these particular functions, I may hint to him, that they are— 
observation, reflection, and judgment. 
Ishall now, Sir, state some of my reasons for asserting, that the 
organs of sense being those of sensation, and the cerebrum that of 
mental operation, the cerebellum is the organ of volition, or rather 
of all the motions of animals, voluntary and involuntary. 
1. There are three distinct intellectual organs or classes of intel- 
lectual organs, namely, the organs of sense, the cerebrum, and 
the cerebellum.—That the cerebellum, though separated from the 
cerebrum only by membranes in man, is not on that account less 
distinct from it than are the organs of sense separated by bony 
plates, is rendered evident by the consideration, that membranes 
form, in the one case, as effectual a separation as bony plates do in 
the other; that many animals* have a bony tentorium between 
the cerebrum and cerebellum, as they have bony plates between the 
cerebrum and face; and that others (birds) have membranes be- 
tween the cerebrum and face, as they have a membranous tento- 
rium between the cerebrum and cerebellum. 
. 2, There are three distinct intellectual functions or classes of in- 
tellectual functions, namely, sensation, mental operation, f and 
volition. 
3. Of the organs, those of the senses are the first, the cerebrum 
* Viz, most species of the cat and bear kind, the martin (mustela martes), the 
coaita (cercopithecus paniscus), and others, 
+ Including observation, reflection, aud judgment, and the subordinate facal- 
ties analyzed by Gall aud Spurzheim. 
