Rabbi Jacobs provides an overview of the history of halakhah through the different sources of the halakhic corpus. His survey starts with the Bible, the Written Torah, and then expounds on its relationship with the Oral Torah. Indeed, the Talmud, committed to writing in the late Antiquity, became the final authority in Jewish Law despite the stated primacy of the revealed word of God in the Bible.
He then moves on to describe the different sources of law which appeared in the medieval and modern periods, demonstrating that a constant need for re-examination and further deliberation proved necessary in light of changing historical circumstances. The authority therefore fell upon local halakhic experts, in the form of responsa literature, leading to the fragmentation in Jewish law which today separates, among others, Ashkenazim from Sefardim.
In some final comments, Rabbi Jacobs provides insights into more recent developments in halakhic adjudication, including an attempt made at the time of the establishment of the State of Israel to reintroduce a Sanhedrin.