We are all familiar with the commandment to 'love your neighbour as yourself'. But it's difficult to know exactly what it means, There are three main problems - firstly, what is meant by 'love', secondly who is (and is not) your neighbour, and finally what does 'as yourself' mean? It's not as simple as it looks at first glance.Of course, it's not just us, today, who are asking these questions. The commandment has been interrogated and analysed for thousands of years, within the Jewish tradition and within the Christian tradition. Each generation, each new blast of scholarship, added a new layer of meaning to the plain sense of the biblical text.This book serves as a partial biography of the commandment, examining the commandment through three lenses. The first lens is the lens of Biblical scholarship and literary criticism. What does each word mean, on its own and in context. Did the words mean something very different to the Israelites at Sinai or the Judeans who first heard the Torah read out at the time of Ezra? What can we learn from comparing the Biblical text to texts from other cultures from the Ancient Near East. The second lens is the lens of Rabbinic Judaism. In particular, the midrash (legend) recorded three times in ancient Rabbinic texts (from 100 BCE to 700 CE) that the famous Rabbi Akiva debated with his colleague Simeon Ben Azzai as to which commandment was the principal or greatest commandment in Torah. Why might Rabbi Akiva have selected the commandment 'love your neighbour'? Why did Ben Azzai disagree? What can we learn from these ancient Rabbinic texts as to what the commandment meant to the Jews of late antiquity? The final lens is that of twentieth century Jewish philosophy. The commandment 'love your neighbour' was central to the work of two Jewish philosophers - one, Franz Rosenzweig who lived, worked and died in Germany prior to the Second World War; the other, Emmanuel Levinas, the Ethicist and Holocaust survivor. Both Rosenzweig and Levinas lived and worked in a cultural milieu where Jewish, Christian and Secular philosophies intermingled. Rosenzweig's world was one of Christian ascendency, and his life's work was to create a method for Jews and Christians to co-exist. Levinas saw that Philosophy had been used and abused by the Nazis to justify their own warped sense of superiority. He also found himself leading the shocked post-war Jewish community of France into reclaiming and revivifying their Jewish identity. In both cases, the commandment to 'love your neighbour' became a central premise to life in modernity - a premise as important to Jews and Christians as to those of no religion at all.This book provides a deep, scholarly and spiritually sensitive analysis of the commandment to 'love your neighbour'. Funds raised from its sale will enable further research - notably into the intervening centuries between the Rabbinic period and the emergence of modernity. It will be of interest to anyone with a broad inquiring mind into Judaism, Christianity, inter-faith and humanistic ethics.