What Makes Institutions Just or Unjust?

Jason Brennan gives a sense of the sort of questions examined in the field of political philosophy.

Political Philosophy: An Introduction

https://www.libertarianism.org/books/political-philosophy-introduction

This book serves as an introduction to some of the major theories of justice, to the arguments philosophers have made for and against these theories, and, ultimately, to how to be more thoughtful and rigorous in your own thinking.