TL;DR: In modern Western numerology, number 1 corresponds to the Sun and number 2 to the Moon. That is the convention of one system, spread through Cheiro's Book of Numbers published in London in 1926: Cheiro treats number 1 as the beginning and the creative principle, number 2 as having "the feminine attributes of the Sun", and says himself that he does not explain why each number is assigned as it is. Birth-date numerology took shape in the late 19th and early 20th centuries and merely borrowed the name of Pythagoras; a 2017 test on 806 Nobel laureates found no predictive power in birth numbers.
Why does numerology assign number 1 to the Sun and number 2 to the Moon?
Because the most widespread numerology system today follows Cheiro's convention, not any astronomical or mathematical rule. In Cheiro's Book of Numbers, first published in London in 1926, Cheiro (the pen name of William John Warner, a famous palmist) opens the chapter on number 1 with "The number 1 stands in this symbolism for the Sun" and the chapter on number 2 with "The number 2 stands in symbolism for the Moon"[1].
His reasoning lies within those two chapters. Number 1 is "the beginning, that by which all the rest of the nine numbers were created", for "the basis of all numbers is one, the basis of all life is one"; it represents "all that is creative, individual, and positive"[1]. Number 2 "has the feminine attributes of the Sun"[1]. In his explanation of the seven-pointed seal he calls the Seal of Solomon, the Sun is "the male quality of Creation", while the Moon is the feminine side on the material plane[1].
The pair 1 and 2 is thus built as a positive and negative pair, male and female, and then attached to the two great lights of the sky.
Beyond that symbolic reasoning, Cheiro proves nothing further. He writes that he will proceed "without going into any elaborate description of why this or that influence has been given to any particular number", and asserts that the numbers were given to the planets "in the most distant ages of civilisation" and used by all students of occultism, "Chaldean, Hindu, Egyptian, or Hebrew"[1]. That claim of ancient origin comes with no documentation.
Which celestial bodies did Cheiro assign the nine numbers to?
Cheiro assigns the nine numbers to the Sun, the Moon, the five planets visible to the naked eye plus Uranus and Neptune; the Sun and the Moon alone carry two numbers each. He calls them all "planets" and writes that the solar system has only nine planets[1]. The table below reproduces exactly the list of numbers for the planets and the numbers for the days of the week in the book[1].
| Number | Celestial body according to Cheiro | Day of the week carrying that number |
|---|---|---|
| 1 | Sun | Sunday (pair 1-4) |
| 2 | Moon | Monday (pair 2-7) |
| 3 | Jupiter | Thursday |
| 4 | Uranus | Sunday (pair 1-4) |
| 5 | Mercury | Wednesday |
| 6 | Venus | Friday |
| 7 | Neptune | Monday (pair 2-7) |
| 8 | Saturn | Saturday |
| 9 | Mars | Tuesday |
The Sun and the Moon are "the only two Planets having what is called 'double numbers'"[1]. The pair 1-4 is the Sun joined with Uranus, the pair 2-7 is the Moon joined with Neptune; on the seven-pointed seal, the line runs from the Sun to the Moon, then Mars, Mercury, Jupiter, Venus, Saturn, and from Saturn, "symbol of death", back to the Sun to begin a new cycle[1]. Hence in the book, 1, 2, 4, 7 are "interchangeable numbers": a person with number 1 is said to be compatible with people born on days carrying the numbers 2, 4, 7[1].
In astronomy, the Sun is a star and the Moon is a satellite of the Earth. Calling them planets is the language of ancient astrology, borrowed by numerology.
Who are the people carrying number 1 and number 2 according to Cheiro?
According to Cheiro, a person's number is the day of birth in the Gregorian calendar reduced to a single digit: a person born on the 1st, 10th, 19th or 28th carries number 1, a person born on the 2nd, 11th, 20th or 29th carries number 2[1]. The following table compares the two numbers according to the exact categories in the book[1].
| Category | Number 1, Sun | Number 2, Moon |
|---|---|---|
| Birth dates | 1, 10, 19, 28 | 2, 11, 20, 29 |
| Period when traits are clearest | 21 July to 28 August ("House of the Sun") and 21 March to 28 April | 20 June to 27 July ("House of the Moon") |
| Traits assigned | creative, original, clear in their views, and therefore rather stubborn and decisive | gentle, imaginative, inclined to art, romantic; creative in mind but less fierce in execution |
| "Lucky" days of the week | Sunday, Monday | Sunday, Monday, Friday |
| "Lucky" colours | shades of golden yellow, yellow, copper through to golden brown | shades of green, cream, white |
| "Lucky" stones | topaz, amber, yellow diamond | pearl, moonstone, light green stone, jade |
Cheiro writes that a person with number 1 and a person with number 2 are "decidedly opposite in their characters", yet "their vibrations are harmonious" and they make good combinations, precisely because number 2 has the feminine attributes of the Sun[1].
How does Cheiro's calculation differ from the life path number calculation?
Cheiro uses only the day of the month, whereas the method common today adds the day, month and year of birth, so the same person can come out with two different numbers. Jeremy Genovese (2017) describes the second method through the example of Barack Obama, born on 4 August 1961: 4 + 8 + 1961 = 1973, then 1 + 9 + 7 + 3 = 20, then 2 + 0 = 2. He also notes that books do not even agree on the name of this number: "birth number", "life path number", "astral number", "fate number", "Fadic number".
Take a person born on 28 March 1990: according to Cheiro, 2 + 8 = 10, then 1 + 0 = 1, that person carries number 1, the number of the Sun; adding every digit of the full date gives 2 + 8 + 3 + 1 + 9 + 9 + 0 = 32, then 3 + 2 = 5. The gap is even larger in systems that keep 11 and 22 as "master numbers": Genovese points out that in that case the order of addition changes the result. For 5 May 1999, adding cumulatively gives 5 + 5 + 1 + 9 + 9 + 9 = 38, then 3 + 8 = 11; adding in groups gives 5 + 5 = 10 reduced to 1, 1 + 9 + 9 + 9 = 28 reduced to 1, then 1 + 1 = 2.
Does numerology really originate from Pythagoras?
There is no such evidence. Genovese (2017), citing Underwood Dudley (1997), writes that the followers of Pythagoras did assign mystical properties to numbers, for instance odd numbers being male and even numbers female, but there is no evidence that they used the birth-date divination technique of modern numerology. The origin of modern numerology is unclear; Dudley suggests L. Dow Balliett may have been the initiator, though perhaps not the first, and Balliett wrote many influential books in the early 20th century. Genovese also notes that in a 1912 memoir, Cheiro said numerology had Indian origins, where he learned it in his youth.
Balliett herself placed her system under the name of Pythagoras: the book How to Attain Success Through the Strength of Vibration carries the subtitle "A System of Numbers as Taught by Pythagoras", and chapter I opens with the idea that from the middle of the 6th century BC, when Pythagoras gave the Greeks his system of numbers, every generation has been drawn to that theory[2]. Cheiro also writes that "one of the greatest of Pythagoras' teachings was that of the occult value of numbers", and that "in this theory he was undoubtedly right"[1].
Those two citations are the way the modern system attaches itself to an ancient name, not documentation about origins.
Can numerology based on birth date predict anything?
Direct testing does not find that. Jeremy Genovese (Cleveland State University) calculated the birth numbers of 806 Nobel laureates from 1901 to 2010 and published the results in 2017 in the Journal of Articles in Support of the Null Hypothesis: the distribution of birth numbers did not differ significantly from random (χ2 = 4.92; df = 8; p = 0.77), and neither did it differ across the six prize categories (χ2 = 28.9; df = 40; p = 0.90). He concludes: "These results provide no support for the claims of numerology."
A test on Nobel laureates only tests one specific claim, not every personality description. But Cheiro's descriptions likewise come with no measurement, so they belong to the category of system beliefs, not verified knowledge.
Nhật Nguyệt's suggestion when reading number 1 and number 2
Nhật Nguyệt's suggestion: when a book or a page says "number 1 is the Sun", ask which system it follows and whether it calculates the number from the day of the month or from the full day, month and year, because the two methods give two different results for the same person. Do not use this number to choose a career, choose a partner or decide money matters. If you want to understand the system, read Cheiro's original text; if you want to know how far it holds up, read Genovese's test.
