Introduction

This chapter introduces the theoretical investigation of the principle of non-contradiction (PNC) that we will undertake in the following chapters. Since the scope of the book is theoretical, not historical-philosophical, we do not aim to reconstruct all the debates and discussions surrounding this principle in the history of philosophy, but to show that modern discussion has mainly focused on the elenctic defence of the principle, without investigating the formulation of the principle itself, i.e., the formal definition of the principle, that appears in Book IV of the Metaphysics, and without problematising the concept of negation, which is essential to its constitution. Instead, as we think that the latter is needed, we will devote the following chapters to it.