The Descendant

Partnership, marriage, open enemies — the other person.

The seventh house begins at the Descendant — the western horizon, the degree setting as the Ascendant rises. It is exactly 180° from the first, in every house system without exception.

Angular. Where the first is the self met on sight, the seventh is whoever is across the table: spouse, partner, contracting party, open opponent. The tradition makes no distinction between ally and adversary here, which is a sharper observation than it first appears.

Because the axis is exact, anything said about the first house is a statement about the seventh as well. They are one line through the chart, not two points.

Angular, which is the houses' cardinal

Houses 1, 4, 7 and 10 — the four that begin at an angle of the chart. They are where a chart meets the world, and they carry the most weight in every tradition that weighs houses at all.

The parallel with the signs is exact rather than a metaphor. Cardinal signs sit three apart in the zodiac; angular houses sit three apart in the wheel. Both divisions are the circle cut into three, and both put the opening term at the point where something begins — an equinox or solstice for the signs, an angle of the chart for the houses. This house shares its class with the first, fourth and tenth.

How wide it really is

Placidus and the other quadrant systems divide time, not arc, so a house's width in the zodiac depends on which degree happens to be rising — and that changes through the day and with the latitude of the birthplace. Sampled every ten minutes across a full rotation, here is how far the seventh house stretches:

The mean is 30° at every latitude, and that is not a coincidence or an artefact of the sampling: over a full rotation each house passes across the entire zodiac, so twelve houses sharing 360° must average exactly thirty. All of the inequality is in the spread, which is why an averaged figure tells you nothing and the range tells you everything. The first house has an identical span in every chart, since its cusps are exactly 180° from this one.

Traditionally attributed

Marriage, contract, alliance, and the open opponent.

Listed because it is what the tradition says, not because this site can check it. Everything above this line is geometry; everything in it is convention.