On The Soul   

could mind possibly think? Will it think with any one indifferently of

its parts? In this case, the 'part' must be understood either in the

sense of a spatial magnitude or in the sense of a point (if a point

can be called a part of a spatial magnitude). If we accept the

latter alternative, the points being infinite in number, obviously the

mind can never exhaustively traverse them; if the former, the mind

must think the same thing over and over again, indeed an infinite

number of times (whereas it is manifestly possible to think a thing

once only). If contact of any part whatsoever of itself with the

object is all that is required, why need mind move in a circle, or

indeed possess magnitude at all? On the other hand, if contact with

the whole circle is necessary, what meaning can be given to the

contact of the parts? Further, how could what has no parts think

what has parts, or what has parts think what has none? We must

identify the circle referred to with mind; for it is mind whose

movement is thinking, and it is the circle whose movement is

revolution, so that if thinking is a movement of revolution, the

circle which has this characteristic movement must be mind.

If the circular movement is eternal, there must be something which

mind is always thinking-what can this be? For all practical

processes of thinking have limits-they all go on for the sake of

something outside the process, and all theoretical processes come to a

close in the same way as the phrases in speech which express processes

and results of thinking. Every such linguistic phrase is either

definitory or demonstrative. Demonstration has both a starting-point

and may be said to end in a conclusion or inferred result; even if the

process never reaches final completion, at any rate it never returns

upon itself again to its starting-point, it goes on assuming a fresh

middle term or a fresh extreme, and moves straight forward, but

circular movement returns to its starting-point. Definitions, too, are

closed groups of terms.

Further, if the same revolution is repeated, mind must repeatedly