Arabic Parts in Astrology

Arabic parts (also called Arabic lots) are sensitive points in the birth chart calculated by combining the positions of three chart factors, typically the Ascendant, a planet, and another planet or lot. The resulting degree acts like a secondary placement, revealing themes that no single planet captures on its own.

The technique originated in Hellenistic astrology with Greek-speaking astrologers like Vettius Valens (2nd century CE) and Paulus Alexandrinus (4th century CE). Medieval Arabic-era scholars preserved, expanded, and systematized the method, which is why the Western tradition calls them “Arabic” parts despite their earlier Greek roots.

The basic formula takes the form: Lot = ASC + Planet A − Planet B. You add the longitude of one planet to the Ascendant, then subtract another. The result is reduced to a position within the 360-degree zodiac, placing the lot in a sign and house.

The seven Hermetic Lots form a coherent system attributed to Hermes Trismegistus. Each lot is assigned to one of the seven visible planets, creating a complete map of human experience:

• Fortune (Moon): material circumstances, bodily health, and what life gives you without effort.
• Spirit (Sun): willpower, career direction, and what you consciously choose to do.
• Eros (Venus): desire, creative passion, and what the soul yearns for.
• Necessity (Mercury): duty, obligation, and the constraints fate places on your path.
• Courage (Mars): boldness, initiative, and where you find the nerve to act.
• Victory (Jupiter): success, achievement, and where rewards arrive most naturally.
• Nemesis (Saturn): tests, necessary difficulty, and where growth demands confrontation.

Together, these seven lots describe the full spectrum from luck to labor, from desire to discipline. The Fortune–Spirit axis sits at the center, and the remaining five elaborate the picture through Venus, Mercury, Mars, Jupiter, and Saturn.

Most Hermetic Lot formulas reverse for night births. If the Sun was below the horizon when you were born (a night chart), the two planetary factors in the formula swap places. This reversal is rooted in the concept of sect, the ancient division between day and night that assigns different roles to each planet depending on when you were born.

For example, the Part of Fortune uses ASC + Moon − Sun by day, but ASC + Sun − Moon by night. The Lot of Spirit uses the exact reverse. This means Fortune and Spirit always sit at the same angular distance from the Ascendant but on opposite sides.

Using the correct sect formula is essential. A miscalculated lot can land in the wrong sign and house entirely, producing misleading interpretations. Our calculators handle this automatically based on your birth time.

Once you know the zodiac sign and house of each lot, interpretation follows the same principles as reading any chart placement:

• Sign describes the style: how the lot's theme expresses. Fortune in Aries acts differently from Fortune in Pisces.
• House shows the life area where that theme plays out. Fortune in the 10th house channels material luck through career and public standing.
• Ruler connects the lot to a planet in your chart. The planet that rules the lot's sign becomes its steward, and that planet's condition (sign, house, aspects) colors how well the lot can deliver its promise.
• Aspects from planets to the lot modify its expression. A conjunction with Jupiter amplifies; a square from Saturn adds friction and delay.

Start with Fortune and Spirit to understand your luck-versus-agency axis, then layer in the other five lots for a more complete picture of fate, desire, and willpower in your chart.