The legal side of Judaism, in contradistinction to Aggadah; the latter embracing all the non-legal ideas. In the earliest Rabbinic period, the term Halakhah (from the root halakh, ‘to go’ or ‘to walk’) was confined to a particular ruling or decision. But, subsequently, while the original meaning was retained, the term Halakhah was also and chiefly used for the whole system. The Halakhah came to denote that aspect of Judaism which is concerned with Jewish law as a whole; the rules and regulations by which the Jew ‘walks’ through life.
In every version of Orthodox Judaism, the Halakhah in its traditional form is sacrosanct as the sole guide for the application of the law to Jewish life. Some Orthodox scholars, fully aware of the findings of modern scholarship, tend to draw a distinction between theory and practice. The scholar can and should have an open mind on the question of how the Halakhah has come to be, while following scrupulously the demands of the Halakhah in practice. The one is a matter of pure scholarship, the other of religion in action. To take an illustration from the Hebrew language, a scholar may investigate the origin and development of Hebrew as a Semitic language but his researches will in no way affect his use of Hebrew in prayer and worship since this language and no other, whatever its origins and development, became the ‘sacred tongue’. Reform Judaism, from the beginning, had a far lesser appreciation of the role of the Halakhah in Judaism, preferring to see the religion more in terms of the prophetic thrust in the direction of ethical monotheism. In more recent years, however, Reform has acquired a new respect for the Halakhah, at least in those areas, such as in synagogal life, where many Reform Jews wish to follow the traditional norms where these are not in conflict with Reform ideology. Conservative Judaism adopts a middle-of-the-road stance, accepting the traditional Halakhah in broad terms but feeling free to allow historical considerations to have a voice in Halakhic application.