His most famous work is The Concept of Law (1961; 3rd edition, 2012), which has been hailed as "the most important work of legal philosophy written in the twentieth century".
Karyanya yang paling dikenal adalah The Concept of Law (1961; edisi ketiga, 2012), yang telah dipuji sebagai "karya mengenai filsafat hukum paling penting pada abad ke-20".