CHART INTERPRETATION: MODERN VS ANCIENT ASTROLOGY

There are a few major differences in how modern astrology interprets a chart vs ancient astrology.

1. Modern astrology tends to equate signs, planets, and houses. While there is some overlap between planets and the signs they rule, from a traditional standpoint, there's no basis for equating, say, Mars or Aries with the first house. Modern astrology tends to interpret a planet in a sign or its modern equivalent house in the same way, while ancient astrology treats these very differently.

2. Ancient astrology uses only the seven visible planets as sign rulers. Modern astrology has tried to assign rulerships to the outer planets based on an affinity those planets seem to have with the symbolism of some of the signs, but traditional rulership is based on the geometrical structure of the Thema Mundi, not on planet/sign affinities.

3. Modern astrology usually uses Placidus or other other house systems that create houses of unequal size, where a house can contain anywhere from 1-3 signs. Ancient astrology used whole sign houses, with each house being of equal size and matching up to a particular sign. You might find that some of your natal planets change houses depending on which system you use.

4. Planetary condition is a major conceptual shift. Modern astrology tends to treat all planets equally in terms of their capacity to execute their agenda and interpretation relies heavily on blending together various combinations of keywords related to the planet and its sign/house. In ancient astrology, planets don't all have the same strength in a chart and their ability to manifest their significations depends heavily on whether it is well or poorly placed. Ancient astrology engages in exhaustive analysis of planetary condition before determining how significations may manifest. Learning how to determine planetary condition in a chart is foundational to ancient astrology but often skipped over by modern astrology.