Although "Love your fellow as yourself" is, as Rabbi Akiva taught, the great underlying principle of the Torah, achieving the experience of this love is a profound challenge for most people. Human personality is instead often given to baseless hatred. The discourse Heichaltzu (lit., "Arm yourselves") by the fifth Lubavitcher Rebbe deals with the spiritual roots of such hatred, its practical consequences, and the remedies for it. Includes several related essays and letters, as well as extensive footnotes and references.