It is by the breaks, the turnings in the road that we cognise its course.
But to cognise how great it is always requires some other magnitude as a measure.
I therefore ascribe this property to man as a property by means of which I cognise him.
So that before we can speak of bodies, we must first cognise our own.
Does it not seem as though, since the motions or states are all that we cognise, they should be all that we need take account of?