Aristotle
Author: Jelte
Plato’s Collected Works
Plato
A Treatise on Human Nature
David Hume
The Structure of Scientific Revolutions

Thomas S. Kuhn
Scientific knowledge evolves through paradigm shifts, argues Kuhn in this highly influential work.
Sein und Zeit

Martin Heidegger
[Being and Time]
On the Genealogy of Morality
Friedrich Nietzsche
Is there anyone else?
The Blue and Brown Books

Ludwig Wittgenstein
Hailed by some as the ultimate introduction to Language and Truth, I personally consider them boring and repetitive.
Beyond Good and Evil
Friedrich Nietzsche
The Astonishing Hypothesis

Francis Crick
A good argument in favour of the philosophy of Materialism. The content almost makes up for what it lacks in humility.
Against Method

Paul Feyerabend
A hugely entertaining and unique anarchistic philosophy of science. To progress knowledge, “anything goes”: propaganda, subterfuge, …