Ambient

Definition

"The Ambient" is Ashmand's English for Ptolemy's to periechon (Greek τὸ περιέχον, "that which surrounds, the encompassing") — the celestial-and-sublunary medium through which the heavens' influence reaches the earth. A power springing from the aether spreads through and saturates the whole atmosphere, and the shifting aspects of Sun, Moon, and stars work on earthly things through it. It is at once the configured heaven and the channel of its action.

In Tradition

In the opening of the Tetrabiblos, Ptolemy founds the whole art on the Ambient. Fire and air, the first sublunary elements, are encompassed and altered by the motions of the aether; they in turn encompass and alter earth, water, and all that lives. The Ambient is thus both the medium and the proximate cause of celestial influence below. He admits only predictions that trace their causes to it. At conception the Ambient stamps its quality on the nascent matter; at birth it answers sympathetically to that first imprint. Certain of its places are appointed as the marks toward which all inference is aimed.

In Practice

This is the philosophical bedrock under the technique, so it shapes how you understand why a chart should mean anything at all rather than giving you something to calculate. The Ambient frames the chart as a reading of one configured moment of an encompassing heaven whose power genuinely pervades the air around us. Ptolemy's discipline follows from it: keep your inferences tied to the Ambient's real influences and the marked places it appoints, and set aside claims that cannot be traced back to that natural cause.

Historical Origin

The concept is set out in Claudius Ptolemy, Tetrabiblos Book I, chapters 1-2 (trans. J. M. Ashmand, pp. 15-17), where the Ambient grounds the naturalistic doctrine, and is reapplied in Book III, chapters 1-4 (pp. 114-124) for the configured heaven at conception and birth.

Etymology

Origin: Greek. Meaning: that which surrounds; the encompassing.

Further Reading

• Claudius Ptolemy, Tetrabiblos
• Chris Brennan, Hellenistic Astrology