On the Fourfold Root of the Principle of Sufficient Reason was written as an academic dissertation in 1813 when Schopenhauer was twenty-five. He presented it to the University of Jena, was awarded the degree of doctor of philosophy on the strength of it, and in the same year paid to have it published. Almost immediately afterwards he set himself to writing what was to be his major work, The World as Will and Representation, and this he completed in 1818. Many years later, he substantially revised and added to the Fourfold Root, publishing a second edition of it in 1847.

In his preface to this second edition, Schopenhauer refers to the Fourfold Root as ‘a treatise on elementary philosophy,’ and within limits that is precisely what it is. Consequently, it can profitably be read, especially in its first edition, as a self-contained treatise on the nature and structure of the world of common sense and science, and on the principles of knowledge, explanation, and necessity governing that world. But Schopenhauer also says in his second-edition preface that the Fourfold Root became the foundation of his ‘entire system,’ and almost from the start that is how he regarded it.