etails cf. the able monograph of Dr. Anton Koch, 1881.]

Thus not every volition, _e.g._ sensuous desire, is action nor all
perception, _e.g._ that of the pure intellect, passion. Finally, certain
psychical phenomena fall indifferently under the head of perception or of
volition, _e.g._, pain, which is both an indistinct idea of something and
an impulse to shun it. In accordance with these emendations, and omitting
certain disturbing points of secondary importance, the matter may be thus
represented:

COGITATIO.
|
|
ACTIO | PASSIO
|
|
|
(Mens sola; clarae et distinctae | (Mens unita cum corpore;
ideae.) | confusae ideae.)
|
VOLITIO: |
6. Voluntas. 3b. Commotiones | 3a. Affectus. 2. Appetitus naturales.
| intellectuales| | |
| | \ /
| | --------v-------
Judicium. | Sensus interni
---------------------------------+-----------------------------------
|
|
PERCEPTIO: 4. Imaginatio
------^------
/ \
5. Intellectus 4b. Phantasia. | 4a. Memoria. 1. Sensus externi.

Accordingly six grades of mental function are to be distinguished: (1)
The external senses. (2) The natural appetites. (3) The passions (which,
together with the natural appetites, constitute the internal senses,
and from which the mental emotions produced by the intellect are quite
distinct). (4) The imagination with its two divisions, passive memory and
active phantasy. (5) The intellect or reason. (6) The will. These various
stages or faculties are, however, not distinct parts of the soul, as in the
old psychology, in opposition to which Descartes emphatically defends the
_unity of the soul_. It is one and the same psychical power that exercises
the higher and the lower, the rational and the sensuous, the practical and
the theoretical activities.

Of the mental functions, whether representative images, perceptions, or
volitions, a part are