Start with high-confidence philosophy overviews books, then narrow by subgenre or adjacent topics.
A History of Philosophy, Volume 2: Medieval Philosophy
Frederick Copleston, Frederick Charles Copleston
Philosophy of Social Science
Michael Root
History of Western Philosophy
Bertrand Russell
The Law of Nations
Emer de Vattel, Béla Kapossy
The Age of Wonder
Richard Holmes
All Things Shining
Hubert Dreyfus, Sean Dorrance Kelly
The Critique of Judgement
Immanuel Kant
