parsing the title of Newton's opus magnum [View all]

[Lionel Mandrake]

Newton published the most important book in the history of science in 1687. The title of this great book is

Philosophiæ Naturalis Principia Mathematica.

The usual English translation is "Mathematical Principles of Natural Philosophy". Obviously the book is in Latin. What is the syntax of the title? I'm no Latin scholar, but here's my take on it.

The title is a noun phrase in nominative case. The word "prīncipia" is the plural of the neuter noun "prīncipium", which means "principle".

"Prīncipia" is modified by the form of the adjective "mathēmaticus" that agrees with "prīncipia" in case, number, and gender. "Mathēmaticus" is a regular first and second declension adjective meaning "mathematical".

"Philosophiæ" is the genitive singular of the feminine noun "philosophia", which means philosophy. The phrase "prīncipia philosophiæ" (which is the title of a 1644 book by René Descartes) is usually translated "principles of philosophy", but a more literal translation would be "philosophy's principles".

"Nātūrālis" is a third-declension two-termination adjective. Here it agrees with "philosophia" in case, number, and gender. The meaning is "natural", i.e., pertaining to nature.