I am planning to read Spinoza's Ethics, Geometrically Demonstrated, and before I read a work I peruse throughout the work, keeping note of headings, as well as read the table of contents, to get a general idea of the structure of the work. The system of axioms and propositions was very similar to Euclid's work on geometry, as well as Newton's Principia Mathematica. The name ("geometrically demonstrated"), implies that this structure was intentional and is derived from Euclid's work.
What struck me about this structure was that I had not found it while reading Descarte, Hume or other philosopher's works. Most works, however structured, seem to be written more in an essay like format rather than being composed of axioms and propositions with the occasional scholium.
My question, thus, is why does Spinoza "geometrically demonstrate" his philosophical worl ('ethics), i.e. why does he structure his work like Euclids? Is my conclusion that he structured it intentionally, which appears to be confirmed by wikipedia (a recourse which is not very credible according to my teachers), correct? Does he do it to serve a philosophical purpose, because it was the style of the time, or for a completely different reason?
Note: I haven't yet started read the Ethics, Geometrically Demonstrated, (having just perused the work), so if this question is elucidated by a reading, then please let me know (esp. if there is a relevant section), though in additon please explain or summarize the reasons why in additon.