Hi Martin

Well here's a friendly challenge then (I know you love them) - find a reference in the Almagest to *anything* that is reservedly astrological, in the way that the astrological houses are a reservedly astrological technique. It is the total absence of anything that is fundamentally astrological or symbolic (as opposed to pure astronomy and mathematics) that made me say that he had no reason to describe his approach to house division in that work.

But I'm not sure I understand the point that is being made, or whether people think that I am claiming Ptolemy used Placidus. For the record, I'm not ! I see that as conceivably possible, but far from proven, and was happy to accept the comments made above in response to my question.

Deb

Hi Deb,

Well here's a friendly challenge then (I know you love them) - find a reference in the Almagest to *anything* that is reservedly astrological, in the way that the astrological houses are a reservedly astrological technique.

Oh, I'm happy to accept there are none. But there are those who would try to divine Ptolemy's preferred system of domification from passages in that text.

But I'm not sure I understand the point that is being made, or whether people think that I am claiming Ptolemy used Placidus. For the record, I'm not ! I see that as conceivably possible, but far from proven, and was happy to accept the comments made above in response to my question.

It's a possible, but an improbable possible. The point I wanted to make was very simple: if Ptolemy had meant for the sky to be divided into astrological houses according to some principle mentioned in the Almagest, then he would have said so -- either in the Almagest itself or in his little tract on astrology (the Tetrabiblos), which does contain a certain amount of calculations. As he didn't say so, there is no reason to believe that he had such an idea in the first place -- no reason, that is, except that Placidus wanted it to be true.