The planets and their functions
If the signs say how and the houses say where, the planets say what. They are the functions at play: the different forces operating within a person. In astrology, "planet" is used broadly and also includes the Sun and the Moon, which are technically luminaries. Each one represents a specific psychic principle, a way of functioning.
It helps to read them as inner functions, not as external characters or as causes that "make" you do something. The Sun forces nothing on you: it names your principle of identity. Mars does not make you aggressive: it names your way of wanting and acting. The sign a planet is in nuances how that function operates; the house indicates where it is expressed most strongly.
The ten, grouped by speed and reach, which is how they are best understood:
The luminaries — the two main lights, the axis of every chart.
- Sun — identity, will, conscious direction. Who you want to become.
- Moon — emotion, instinct, memory, the need for safety. Where you set out from.
The personal planets — the fastest, the ones that most differentiate one person from another.
- Mercury — thought, communication, learning.
- Venus — affection, worth, pleasure, aesthetic sense.
- Mars — desire, action, energy, the way of facing conflict.
The social planets — the bridge between the individual and the world.
- Jupiter — expansion, meaning, confidence, growth (and the risk of excess).
- Saturn — limit, structure, responsibility, the maturity built through effort.
The transpersonal planets — the slowest; their sign is generational, and in the individual chart it is above all their house and aspects that weigh.
- Uranus — rupture, originality, sudden change.
- Neptune — sensitivity, the dissolving of limits, spirituality, also confusion.
- Pluto — deep transformation, power, what dies to be reborn.
How they are recognised in the chart: each planet appears with its sign and its house —for example, "Mars in Libra, house 10"— and that is already a unit of reading: the function (Mars, action), the manner (Libra, seeking agreement) and the terrain (house 10, public life). The personal planets and the luminaries are read first, because they most define individual character. The transpersonal planets are read by house and by the aspects they form with the rest, rather than by their sign.
We now have the what, the how and the where. What remains is to see how these functions relate to one another: those are the aspects.