For the doctrine of being, the statement holds: Being is essence; similarly, for the doctrine of essence: Essence is being. This being, which essence constitutes, is the essential being, existence, the existent, or the thing. Initially, this appears as something immediate. However, as it continues to determine itself, reflection reveals itself as its ground. It negates its immediacy, so that it proves to be a determined being. This means that the appearance emerges as the truth of the thing. As the unity of essence and existence, reality arises. In this study edition, based on the historical-critical edition, the "Doctrine of Essence" appears for the first time since 1819 as an independent volume, thus following the original publication history of the "Science of Logic." It includes the notes from the historical-critical edition.