Philosophers debate six big questions: Are Boltzmann Brains Bad? Does Mathematical Explanation Require Mathematical Truth? Does Quantum Mechanics Suggest Spacetime is Non-Fundamental? Is Evolution Fundamental When It Comes to Defining Biological Ontology? Is Chance Ontologically Fundamental? Are Sexes Natural Kinds?

Introduction Part I: Are Boltzmann Brains Bad? 1. Why Boltzmann Brains Are Bad 2. What Follows from the Possibility of Boltzmann Brains? Part II: Does Mathematical Explanation Require Mathematical Truth? 3. Mathematical Explanation Requires Mathematical Truth 4. Mathematical Explanation Doesn't Require Mathematical Truth Part III: Does Quantum Mechanics Suggest Spacetime is Non-fundamental? 5. Against Wavefunction Realism 6. Separability, Locality, and Higher Dimensions in Quantum Mechanics Part IV: Is Evolution Fundamental When it Comes to Defining Biological Ontology? 7. Is Evolution Fundamental When It Comes to Biological Ontology? 8. Is Evolution Fundamental When It Comes to Defining Biological Ontology? Yes Part V: Is Chance Ontologically Fundamental? 9. Chance and the Great Divide 10. On Chance (or, Why I am Only a Half-Humean) Part VI: Are Sexes Natural Kinds? 11. Are Sexes Natural Kinds? 12 The Animal Sexes as Historical Explanatory Kinds