Derech HaShem (The "Way of God") is a philosophical text written in the early 1740s by Rabbi Moshe Chaim Luzzatto. It is considered one of the quintessential handbooks of Jewish thought.
The text covers a vast gamut of philosophical topics in the vast spectrum of classical Judaism's outlook on the world. These topics include the purpose of creation, the Creator, human responsibility, the spiritual realms, providence, Israel and the nations, astrology, the human soul, theurgy, prophecy, the study of Torah, prayer, and the function of mitzvah observance. All these are brought in a clear flowing structure that outlines the whole of Jewish thought and philosophy.