Venus rules Taurus and Libra, is exalted in Pisces, in detriment in Aries and Scorpio and in fall in Virgo. Ptolemy gives it a temperate and moist nature, and it is the lesser benefic of the classical scheme, Jupiter being the greater; it belongs to the nocturnal sect. Like Mercury it is an inferior planet and never strays far from the Sun, at most about forty-seven degrees, so it is seen only near dawn or dusk, as morning star or evening star. Its natural significations are love, marriage, pleasure, ornament, music, art, harmony, the young, and, in medical astrology, the kidneys and the reproductive system. The distinction between the morning and evening apparitions is old and was interpreted as two aspects of the same power in Mesopotamian, Greek and Mesoamerican traditions alike.
The Latin name Venus renders the Greek Aphrodite, who in turn renders the Babylonian planet-goddess Ishtar, herself a continuation of the still older Sumerian Inanna, so that the association of this planet with love, beauty and desire is not a Greco-Roman invention but a chain of translation running back through at least three civilisations and well over two thousand years. Ptolemy's Tetrabiblos, part of the Hellenistic synthesis of roughly the first century BCE to the second century CE, explains Venus's temperate, moist quality by her nearness to the Sun for warmth and her own considerable brightness for moisture, the same proximity-based reasoning the text applies to every planet. The morning and evening apparitions that give Venus her double character as herald of dawn and dusk were already tracked as a single body's two faces in Babylonian celestial omen-reading centuries before Ptolemy wrote.