Neptune
Neptune was found in 1846. Like Uranus and Pluto, he stands outside the seven classical planets. He has no traditional domicile, exaltation, detriment, or fall. Modern authors often call him the ruler of Pisces. The traditional ruler of Pisces is Jupiter. This library keeps Jupiter in that chair and gives Neptune his own page, so a reader can see the later poetry without losing the older dignity scheme.
In modern language Neptune describes imagination, compassion, the thinning of a boundary, art, dream, glamour, and the fog that can be mercy or confusion. He is a solvent. He dissolves the hard edge of whatever he touches. Dissolving can be the start of music, prayer, or a kindness that a stricter planet would have refused. Dissolving can also be a refusal to look at a fact. Both belong in an honest sentence. A reading that keeps only the mysticism, or only the warning, is a partial Neptune.
The twelfth house is the natural house of Pisces, so Neptune is often discussed there: withdrawal, the hidden room, institutions, dreams, and compassion without an audience. That is a modern topical echo. It is not a classical planetary joy. Jupiter's traditional relationship to Pisces and the twelfth is the older version of the same neighborhood. Venus, exalted in Pisces, is the other classical guest in Neptune's modern sign. When you read Neptune, it is worth glancing at Jupiter and Venus, because the tradition already had words for mercy and for unbounded union.
Neptune spends about fourteen years in a sign. The sign is generational. The house and the close aspects are personal. Neptune conjunct the Moon is a permeable feeling life, imaginative and sometimes hard to fence. Neptune square the Sun can describe a will that idealizes, or a vitality that leaks into fantasy, and the rest of the chart says which correction is available. A wide aspect to an outer planet is a background hue. A tight aspect to a luminary is a biography.
His retrograde is a large fraction of each year and is ordinary in birth charts. Treat a natal retrograde as a common condition of apparent motion, an inward cast to the imagination, not a special wound. Transiting Neptune is slow enough that a contact to a natal planet is a long season of uncertainty in that topic. The season asks for a cleaner line between image and fact. It does not schedule a revelation, and it does not diagnose a mind.
A beginner can use Neptune last among the modifiers. Read the classical planets, especially Jupiter if Pisces or the twelfth is loud in the chart. Then ask what Neptune dissolves, and whether the dissolution serves a real mercy or a real avoidance. Art is a legitimate answer. So is a boundary put back on purpose. The planet does not choose for the person.
Pythic Cosmos describes Neptune as the modern solvent in the sky. The traditional words for the same neighborhood remain Jupiter's domicile in Pisces and the twelfth house's topics of withdrawal. Use the modern name when you mean the planet discovered in the nineteenth century. Use the traditional names when you mean dignity and house. For the sign, read Pisces. For the older ruler, read Jupiter.