Understanding Ptolemy's "Tetrabiblos"
by Ed Friedlander, M.D.
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As for the nonsense on which many waste their labor and of which not even a plausible account can be given, this we shall dismiss in favor of the primary natural causes.

        -- Claudius Ptolemy, Tetrabiblos

Claudius Ptolemy's contribution to mathematics and astronomy was monumental, one of the great scientific achievements of the ancient world. His Almagest, written in the second century, remained the standard work on astronomical theory and observation until the time of Copernicus.

By contrast, Ptolemy's Tetrabiblos deals with the pseudoscientific use of astronomy to make predictions about human affairs.

This site is under construction. Its purpose is:

When the site is completed, I will argue that:

Ptolemy's Tetrabiblos. The original of the document is online at a Danish site, apparently scanned. I have tried to correct the errors.

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