Many people can spot a Chassidic Jew when they see one, and many can even cite several facts about the Chassidic movement and its leaders.

But what exactly is Chassidism, the philosophical underpinnings of the movement which began in mid-18th century Eastern Europe?

This was the question the Rebbe set out to answer in a landmark talk he delivered in Yiddish on 19 Kislev, 5726 (1965). This talk was later published in Hebrew in 1970 under the title Inyanah Shel Toras Hachasidus. During the course of the talk, the Rebbe elucidates many concepts including defining what the actual contribution Chassidic thought has on Torah study, the relationship Chassidism has with Kabbalah and how it offers a deeper and expanded understanding of Torah.

In 1978, the work was translated into English by Rabbi Heschel Greenberg and Dr. Susan Handelman and edited by Rabbis Zalman I. Posner and Aaron Dov Sufrin and published by Kehot Publication Society as On the Essence of Chasidus (a title chosen by the Rebbe).

Now part of Kehot’s acclaimed Chassidic Heritage Series, it has become a staple in libraries of English-speaking students of Chassidism.

In honor of 10 Shevat, which this year commemorates seventy years of the Rebbe's leadership, Chabad.org and Kehot Publication Society are delighted to release this classic work online.

To aid the student, the Hebrew original and English translation are presented side by side, for easy cross-referencing. It also contains extensive footnotes, which render even the kabbalistic and Talmudic terminology accessible to readers and students of all backgrounds.

The publication is the latest result of the longstanding partnership and synergy between Kehot and Chabad.org. Since the early 1990s, Chabad.org has carried many Kehot texts, and Kehot has published several books produced by Chabad.org. Another notable product of this partnership are the popular Smart Siddur apps, which were developed by the Chabad.org technology team in collaboration with Kehot.

“On behalf of our readers, we are grateful to Kehot for generously sharing this treasure with the worldwide community,” says Chabad.org director Rabbi Meir Simcha Kogan.

The text was expertly and painstakingly digitized and processed by the Chabad.org team, each of whom contributed his or her talents to this special project.

The complete discourse can be viewed in Hebrew and English here.

A handsome hardcover print edition can be purchased from Kehot here.