Since geometry is the right foundation of all painting, I have decided to teach its rudiments and principles to all youngsters eager for art. - Albrecht Dürer

The new art must be based upon science — in particular, upon mathematics, as the most exact, logical, and graphically constructive of the sciences.

Whoever … proves his point and demonstrates the prime truth geometrically should be believed by all the world, for there we are captured.

Sane judgment abhors nothing so much as a picture perpetrated with no technical knowledge, although with plenty of care and diligence. Now the sole reason why painters of this sort are not aware of their own error is that they have not learnt Geometry, without which no one can either be or become an absolute artist; but the blame for this should be laid upon their masters, who are themselves ignorant of this art.