DEDUCTION OF THE KANTIAN CATEGORIES. 549 
Motivity, it will therefore recognize both the receptive unity and the spontaneous plu- 
rality, and from their relation will derive the category of Totality, in which Unity and 
Plurality are both combined. 
348. Motivity, therefore, in the three conditions of intelligence, gives us the three cate- 
gories of Quantity,— Unity, Plurality, and Totality, all of which refer, through the motive 
category of Modality, to the Science of the Possible, and particularly to Mathematical 
Science. 
349. Next in order of prominence as well as of acquisition, are the determinations of 
Spontaneity. The subject cannot regard itself otherwise than as object, and there is there- 
fore more difficulty attending the study of the purely subjective, than we have found in 
the objective, as manifested through Motivity. 
300. Spontaneity is the active, laboring state of the mind, corresponding to the vigor 
of youth and early manhood. In investigating its laws, one of the first inquiries is, What 
influence do we have by our voluntary action over the objects of our cognition, or what 
quality do we communicate to them ? 
351. All impressions of Spontaneity on Motivity, are heel or affirmative. We have, in- 
deed, no power of limitation or of negation, as mere receptive beings, but we assert fully 
and positively, every impression that we receive. ‘Thus, we can never admit that the 
senses deceive us, for the senses are merely media for conveying impressions. We exer- 
cise our attention or spontaneity, together with our senses or motive-rationality, and an 
impression follows, the reality of which is undoubted. A further effort of spontaneity 
is required to interpret the meaning of that impression, and if that secondary effort is in- 
sufficient, we are led into error. ‘The category of Motivity, cognizing the impressions of 
Spontaneity, is therefore Affirmation. 
302. The peculiar office of Spontaneity, particularly when concerned with its own 
actions, or with Reality, of which its actions are the representatives, is to define, limit, and 
give precision to our ideas. 
303. We have seen that what are called delusions of the senses, are properly errors of 
spontaneity. I have, for example, the impression of an object on the optic nerve. Of the 
reality of the impression there can be no doubt, but great care may be necessary to give 
it its proper interpretation. I must first inquire whether the impression is occasioned by 
a disease of the nerve, or by the normal stimulus of an external object. If I am satisfied 
that it proceeds from an outward object, I must then attend to the angles of vision which 
determine the outline, the modulations of light and shade that indicate the form, the, dis- 
tinctness or indistinctness that mark its relative nearness or distance, and enable me to 
judge of its size, the clearness or haziness of the atmosphere, sharpness or obscurity of 
vision, and any other circumstances that may affect my decision. A failure of proper at- 
