How are definitions, axioms, and propositions organized in Spinoza’s Ethics?

In his masterpiece, the Ethics, Benedict de Spinoza organizes his philosophical arguments using a geometric method modeled after Euclid’s Elements and Proclus’s Elements of Theology.12

The structure of the work is as follows:

• Definitions: Spinoza begins by establishing definitions for key technical terms, such as substance, attribute, mode, and God.12
• Axioms: These definitions are followed by a series of self-evident axioms, which serve as the foundational logical principles for his system.12
• Propositions (Theorems): Using these definitions and axioms, Spinoza derives a sequence of propositions (theorems) to develop his metaphysical arguments.12

While the work is primarily an axiomatic proof, it evolves into a hybrid of formal demonstration and philosophical narrative. As the text progresses, Spinoza incorporates explanatory notes, observations, and polemical essays to clarify his conclusions for the reader. This rigorous, geometric presentation was intended to provide greater clarity than the conventional narrative style of his earlier works.12