René Descartes

Philosopher and mathematician · France · 1596–1650

Aries 10.9° · born March 31, 1596
Birth time unknown

Birth date sourced. Birth time unknown.The Moon remained in Taurus throughout that civil day. Mercury crossed from Aries into Taurus during that day, so its sign is left open. Everything below uses only what the complete civil day settles.

The day, read honestly

Four of the nine placements whose signs are settled stand in Aries — the Sun, Jupiter, Uranus and Pluto. The placements whose signs could change with an unknown hour are not counted. A cluster that size becomes the section the rest of the chart plays around.

Positions at 12:00 civil time in Descartes—a reference instant, not a birth time. No houses, rising sign, angles, or sect were computed.

Where the Sun actually stood

The Sun's exact place is 10.9° Aries. That falls in the second decan, 10°–20°, sub-ruled by the Sun in the classical scheme — a fire sign read through a cardinal season.

The personal registers

The personal planets sit Venus at 6.3° Taurus, Mars at 22.2° Gemini. Venus in a earth sign reads as taste for the substantial and the lasting; Mars in a air sign reads as drive that argues its way forward.

The angles that hold

Start where the chart is tightest — Jupiter conjunction Uranus, 0.8° of separation. The tradition stops reading a conjunction as two things. It is one appetite with two names, and it moves together or not at all. Behind it, Jupiter trine Neptune at 1.1°, and Uranus trine Neptune at 1.9° — both still well inside the orbs this site uses. These angles were checked through every hour of that civil day and survive throughout, which is why an unrecorded hour does not disturb them.

The standing structure

The day-stable angles form no closed figure. Nothing funnels; each aspect is its own negotiation, which the tradition reads as a chart of separate treaties rather than one campaign.

The classical map

Of the seven planets the classical scheme judges, three sit in a sign it has an opinion about. The Sun in Aries at 10.9° is in exaltation — the tradition’s honoured-guest placement, working at its best; the Moon in Taurus at 10.0° is in exaltation; Venus in Taurus at 6.3° is in domicile — the planet in its own sign, running on home rules. None of these labels is a verdict on a person; they describe how a function is situated, nothing more.

The shape of the whole

Of the 9 placements whose signs hold for the whole day: 5 in fire, 3 in earth, 1 in air by element, 4 cardinal, 3 fixed, 2 mutable by modality. Fire signs carry the scheme’s forward pressure: heat applied early, patience treated as a later skill. Mercury crossed from Aries into Taurus during that day, so its sign is left open. No settled placement falls in water — an absence the tradition treats as information, not as a defect. Saturn and Neptune were retrograde — the backward drift a body appears to make as the Earth overtakes it, read in the scheme as a function that reviews before it releases.

The Moon, and how far it can move

The Moon stayed in Taurus for the whole of that day at the birthplace, covering 11.8° between midnight and midnight. The sign survives the missing hour; the degree does not, and is given as a reference rather than a fact. At the noon reference it stands at 10.0°.

Where this comes fromSources, revisions, and exactly what this chart assumes

Source article: René Descartes · revision 1365137426
Wikidata: Q9191 · revision 2522332601
Retrieved: 2026-07-26T18:47:50.947Z
Birth date: 1596-03-31 · day precision · proleptic-gregorian
Birthplace: Descartes, France · Q320299
Coordinates: 46.9736, 0.6978 · from Descartes
Reference instant: 1596-03-31T11:50:39.000Z · noon civil time, not a birth time
Omitted: Rising sign, houses, angles, and sect—all require a birth time.
Unknown-time range: Moon travelled 11.79° · The Moon remained in Taurus throughout that civil day.
Open signs: Mercury crossed from Aries into Taurus during that day, so its sign is left open.
Engine: astronomy-engine (repository dependency) · @zodiacs/engine/internal/math
Portrait: After Frans Hals · public domain · Wikimedia Commons

Something wrong here?Ask us to correct or remove it.