How does Ptolemy judge temperament from the planets?

In the Tetrabiblos Ptolemy treats hot, cold, moist and dry as physical qualities. He gives each planet a share of them in Book I, chapter 4, and says that the share changes with the planet’s position in the sky and the season of the zodiac it stands in. In Book III, chapter 11, he tells the astrologer where to look in a birth chart: the rising point of the zodiac and the planet with the most claim to it in the sense he explained in III.2, the planets standing there, and the Moon. He does not give a formula for combining what is found. He ends the chapter by saying that all of it is to be put together as a “conjecture”. This piece follows that path through the text.

The qualities belong to the heavens first

Ptolemy reasons about the four qualities from what can be seen: the Sun’s heat as it nears the zenith, the Moon’s nearness to the earth and its moist vapours, a planet’s distance from the Sun. In Ashmand’s translation of I.4 (page numbers are those of the Foulsham edition): “The Sun is found to produce heat and moderate dryness.” And of Saturn: “Saturn produces cold and dryness, for he is most remote both from the Sun’s heat and from the earth’s vapours. But he is more effective in the production of cold than of dryness.” (Ptolemy, Tetrabiblos I.4, trans. Ashmand, p. 13).

The table below sets out each planet’s share in my own words. Where the two translations differ in emphasis I have said so.

In I.5 Ptolemy sorts the qualities in two: “two of the four humours are fertile and active, the hot and the moist” and the other two, the dry and the cold, are “destructive and passive” (Ptolemy, Tetrabiblos I.5, trans. Robbins, p. 39). He uses that division to explain why the ancients called Jupiter and Venus beneficent and Saturn and Mars the opposite.

The qualities shift with position

Two chapters in Book I say a planet’s quality is not fixed.

Chapter 8. The Moon, from new to first quarter, is more productive of moisture; from first quarter to full, of heat; from full to last quarter, of dryness; and from last quarter to the end of her cycle, of cold. The three superior planets (Saturn, Jupiter and Mars, in Robbins’s note on the text), in oriental aspects only, follow a parallel sequence by their position to the Sun: moist from rising to the first station, hot to the evening rising, dry to the second station, cold to setting (Ptolemy, Tetrabiblos I.8, trans. Robbins, p. 45, and Ashmand, p. 16).

Chapter 10. Spring exceeds in moisture, summer in heat, autumn in dryness and winter in cold. Ptolemy gives a different pattern for the four directions at the horizon: the east is dry, the south hot, the west moist and the north cold. He says that where a planet’s own quality matches the season or direction, its action is purer and stronger, and where it is opposed, weaker (Ptolemy, Tetrabiblos I.10, trans. Robbins, pp. 59–65).

The “angles” in I.10 are the four directions at the horizon, the places the winds come from. They are not houses. I use whole-sign houses, and nothing in this chapter depends on the house system.

Book III, chapter 11: where to look

Book III chapter 11 is titled “Of Bodily Form and Temperament” in Robbins and is chapter XVI of Book III in Ashmand. Ptolemy says to observe the eastern horizon and the planets upon it or taking its rulership “in the way already explained” (Robbins’s note 109 refers the reader to III.2, p. 233, where Ptolemy sets out his own account of rulership), and the Moon, and that “the ruling planets have most power in this matter” (Ptolemy, Tetrabiblos III.11, trans. Robbins, p. 309). By “the eastern horizon” he means the rising point (Robbins note 110; Ashmand p. 101, note 1). Whether a planet counts as “upon” it by degree or by standing in the rising sign, he does not say in this chapter. I use whole-sign houses.

He then goes through the planets. The same chapter describes complexion, hair and build. I set those descriptions aside here, and the two translations differ in several of their words. For the qualities alone, the chapter says the following. The column heads are Ptolemy’s words, “in the orient” and “setting”. The chapter does not say whether “in the orient” refers to the horizon or to the planet’s position east of the Sun.

Venus is said to have effects like Jupiter’s, with no separate statement about her qualities. The luminaries help when they are in aspect to these planets: Robbins has the Moon, when separating from them, tending toward “a more moist temperament” (p. 313); Ashmand says the same of her moisture and ties it to the proportion of her light as explained earlier in the treatise.

The chapter then gives a second reading, by quarters of the zodiac. From the spring equinox to the summer solstice, which is Aries to Gemini in the way Ptolemy defines Aries in I.10, he says the temperament exceeds in the moist and warm. From the summer solstice to the autumn equinox it exceeds in the warm and dry. From the autumn equinox to the winter solstice, in the dry and cold. From the winter solstice to the spring equinox, in the cold and moist.

The chapter ends by saying that all these things are to be gathered. In Robbins, “it is fitting that we should observe and combine all these things and make a conjecture as to the character which results from the mixture” (Ptolemy, Tetrabiblos III.11, trans. Robbins, p. 317). Ashmand’s version is that all these influences are to be borne in mind, “in order that the peculiar properties, observed in their joint temperament, may be so compounded as to authorize an inference therefrom, concerning the form and temperament of the body” (trans. Ashmand, Book III ch. XVI, p. 103).

Where the sources differ or are silent

No weights. Ptolemy gives no scale and no rule for what outweighs what. A rising Saturn gives an excess of moist and cold, a Saturn in a warm quarter pulls the other way, and the text does not say which wins. He calls the result a conjecture.

No named types. The chapter speaks of an excess in two qualities or in one. It does not name the results. The temperament types that later writers built on the four qualities are not in these chapters.

Translations. Robbins and Ashmand agree on the qualities in III.11. They word the descriptions of the body differently (the complexion given to a rising Saturn is one example), and Ashmand’s text follows Proclus’s paraphrase of the Greek, not Ptolemy’s own words.

What he does not say. I.4 gives no number for any share. “Chiefly”, “moderately” and “to a degree” are his words, and the translations render them with different emphasis.

What this does not cover

This piece covers only the qualities in I.4, I.5, I.8, I.10 and III.11. It does not cover Ptolemy’s description of bodily form, the fixed stars’ qualities in I.9, or any later system of temperaments. It does not say what any person’s temperament is.