Manifesto on the Teaching of Mathematics
Being a declaration of the principles on which these works are based.

Intuitive Infinitesimal Calculus
Being a textbook instantiating the aforementioned philosophy.

History of Mathematics
A brief introduction including many readings from original sources.

Intuitive Geometry
A brief course for visual thinkers.

Containing assorted remarks on the foregoing subjects.

Who is the illustrious author of these perceptive writings?