And even if I had not demonstrated this, the nature of my mind is such that I cannot in any case help assenting to the things I clearly perceive, at least, for as long as I clearly perceive them; and I remember that even in past times, when I was as closely attached to the objects of the senses as it is possible to be, I always considered that truths of this kind that I clearly recognized, concerning shapes, or numbers, or other matters belonging to arithmetic or geometry or, in general, pure and abstract mathematics, were the most certain of all.