Just as the light of the sun irradiates the organ of vision and things visible, enabling the former to see and the latter to be seen, so too the irradiation of a spiritual light brings the mind into relation with that which is intelligible.
The consideration of lines, angles and figures is of the greatest utility since it is impossible for natural philosophy to be known without them... All causes of natural effects have to be given through lines, angles and figures, for otherwise it is impossible for the reason why (propter quid) to be known in them.
Power from natural agents may go by a short line, and then in its activity greater... But if by a straight line then its action is stronger and better, as Aristotle says in Book V of the Physics, because nature operates in the shortest way possible. But the straight line is the shortest of all, as he says in the same place.
This part of optics, when well understood, shows us how we may make things a very long distance off appear as if placed very close, and large near things appear very small, and how we may make small things placed at a distance appear any size we want, so that it may be possible for us to read the smallest letters at incredible distances, or to count sand, or seed, or any sort of minute objects.
Every operation in nature is in the shortest, best ordered, briefest, and best possible way.
The diligent investigator of natural phenomena can give the causes of all natural effects... by the rules and roots and foundations given from the power of geometry.
The head is borne towards the heavens and has two lights, as it were the sun and moon.
Vacuum stands and remains a mathematical space. A cube placed in a vacuum would not displace anything, as it would displace air or water in a space already containing those fluids.
In a vacuum which is imagined as infinite there cannot be local differences, both on account of its infinity, and also because of the fact that the vacuum, if it exists, would have no nature but a privation, and therefore it can have no natural differences.
The space of the real physical world must be considered full, that is a plenum, because a vacuum could have no physical existence.