Werner Heisenberg
Category: Erudition
Influential reading
The Hidden Face of God

Gerald Schroeder
Grounding for the Metaphysics of Morals

Immanuel Kant
Although not recommended in translation, this work forms a good introduction to Kant’s moral philosophy. Read it before attempting Metaphysics of Morals.
An Essay Concerning Human Understanding
What a classic! The first persuasive case for a modular cognitive architecture. Words signify ideas or complexes of ideas. A vital introduction for those pondering the important question of Nominalism vs. Realism.
Essay on the Freedom of the Will

Arthur Schopenhauer
Schopenhauer’s renunciation of Free Will. Best understood in conjugation with Kant’s metaphysics of transcendental freedom.
Dreams of a Final Theory
On the Concept of Nature

Alfred North Whitehead
Sets out to constrain as deeply as possible the absolute knowable nature of reality – especially time and space. The best treatment of the philosophical implications of Einstein’s General Theory of Relativity that I have come across.