"Celestial Matters" by Richard Garfinkle

This is some very original novel I recently encountered.

First the AH bits: Alexander the Great's empire never has fallen and expanded, to include Persia, India, and a good part of Atlantea (the Americas, what else). Phoenicians, Indians and native Atlanteans were integrated into their polytheist (guess that helps) society - the main character's bodyguard is a "Xeroki" (Cherokee) e.g. Athens and Sparta have pooled their strengths, so to speak: They've got a great scientific academy, but also a military of a high quality. But for the last millennium (roughly), it's been caught in a war with the "Middle Kingdom" under the 'An dynasty (no idea why Garfinkle writes many words starting with an H like that, but that's just a little quibble). Meanwhile, since technology has progressed, it's even fought in space.

Which leads us to the second part of the premise: In this universe, the old Greek theories apply:

- Four humours/temperaments: Which means if you wanted to calm down someone, you'd inject him phlegm. To make a warrior fight better in battle, you'd inject him blood to make him more sanguine - not ordinary blood, but blood from which all traces of the other humours were removed.

- Ptolemaic universe: Earth is at the center, the other planets (incl. Moon and Sun) go around it while sitting on huge crystal spheres. Epicycles are also considered.

- Four elements: Everything's made of atoms, but there are just four elements of water, air, earth, and fire. Alchemists are able to create elements like air-silver or fire-gold by combining them.

- Not to mention the many alternative names for technology, like firearms, and scientists. What we'd call astronomers are Ouranologists (after Ourania, the muse of astronomy), experts for handling fire are pyrologists, and there are several more.

As said: A good adventure novel with a very original paradigma (no buzzword here) behind it. I think I'll recommend this elsewhere too.

Link: archive.org/details/celestialmatters00garf