Among all the studies of natural causes and reasons, light most delights the contemplators; among the great things of mathematics, the certainty of its demonstrations most illustriously elevates the minds of its investigators; perspective must therefore be preferred to all human discourses and disciplines, in the study in which radiant lines are expounded by means of demonstrations and in which the glory is found not only of mathematics, but also physics: it is adorned with the flowers of one and the other.