Claudius Ptolemaeus, or Ptolemy, lived and worked near Alexandria from roughly 100-170 CE.

He is credited with a remarkable range of work.

In addition to the Mathematical Treatises (a.k.a. Almagest), Ptolemy is known as the author of:

–A Geography – an atlas of the known world, mapped onto a grid system

–A treatise on theoretical astronomy
(a natural philosophy to match the geometry of Almagest)

–The Tetrabiblos, a comprehensive guide to astrology still consulted

–A work on optics

All of these were authoritative works among Greek, Latin and Arabic-speaking scholars for more than a thousand years.

Let that sink in.

A single author is credited with works of geography, astronomy, mathematics, physics, and astrology, each of them unsurpassed for a millennium.

And to be clear, we’re not talking about an encyclopaedist who simply recorded the sum of human knowledge at an historically fortuitous moment (though there’s an element of that). Much of what Ptolemy presents to the world is novel, pushing beyond what earlier investigators had reported.

A single author.

For a thousand years, an unsurpassed authority on much of what today we’d call Science.

A single author.

If that’s true, then we have to look at Ptolemy as a genius of rarefied ability.

However, we really know nothing of Ptolemy as a person. The most influential scientist, mathematician, geographer and astrologer for more than a millennium, the person behind all this work is an historical cipher. His lifespan is estimated from dated observations in Almagest and others of his works; other clues in his writings tell us that he lived and worked near Alexandria. And that’s about all we know of him. Some purported biographical details from authors of many centuries later are generally viewed by modern scholars as medieval fabrications.

One other detail: Several of Ptolemy’s surviving works are addressed to someone named Syrus.
A colleague? Mentor? Patron? It’s not really clear.

There’s an alternative which warrants some consideration.

Perhaps Ptolemy was not an individual, but an academy.

A think-tank.

A group of scholars assembled by the fabulously wealthy scion of some trading-house of Alexandria, tasked with the compilation and extension of all that was known of the stars, the seas, the land.

Or something like that.
When you consider the breadth and depth of Ptolemy’s endeavors, and his position of authority for a dozen centuries, it’s hard to imagine all of this from the mind of a single individual.

Ptolemy as the nom de plume of an academy of scholars seems a reasonable notion.
Which suggests Syrus as a patron.

We’re biased in favor of the hypothesis of Ptolemy as an academy.
Which leads to the question: Is there any hope of resolving this matter?

Well, perhaps there is.

Modern tools of textual analysis have been used to evaluate many ancient documents.
Have such techniques been brought to bear against Ptolemy?

We’d propose that Almagest, and any other of his surviving works would display signs of text-by-committee. (We’ve sufficient experience with t-b-c to know that it leaves a particular imprint upon a final document. But not enough, across different disciplines and languages, to venture suggestions for formal rules of t-b-c textual constructs.)
At the same time, we’d expect the astronomy texts (the Treatises, ‘Handy Tables’ and such) to bear the mark of the same author/team, while unrelated works – say, the Geography, or the Tetrabiblos – might demonstrate a completely distinct authorial voice and style. (Of course, we have to account for the fact that surviving texts of any of these works are copies of copies of copies, with all of the implications that entails.)

Ptolemy a single author? Hard to imagine.
It’s not a matter of ‘who was Ptolemy?’, but rather ‘who were Ptolemy?’.

These are but the musings of an amateur. Take them as such.