Of all the numbers, one has the oddest status. It is the start of counting, yet many ancient thinkers hesitated to call it a number at all, preferring to see it as the source from which numbers come. This article follows that idea through myth, religion and philosophy. It describes what traditions believed and taught, as a history of ideas, and not what is true of the world. The recurring theme is that a single beginning appeals to the human mind as an explanation, and different cultures dressed that appeal in very different stories.
One as the thing before counting
The most careful early statement of the oddity comes from Greek mathematics. In the definitions at the start of Book VII of Euclid’s Elements, a unit is described as that by virtue of which each existing thing is called one, while a number is a multitude made of units. On this view the unit is not itself a number but the thing that makes numbers possible. Aristotle and later commentators discussed one as the principle of number, and the same notion influenced how philosophers talked about the origin of everything else.
The Pythagorean tradition, whose ideas are known mostly through later reports, used the term monad for the single unit and treated it as the first principle from which other numbers and things arise. Much of what is attributed to the early Pythagoreans was written down by later authors, so claims about what the founder himself taught should be held loosely. The broader point is that the idea of a number from which all numbers grow, central to Pythagorean number philosophy, gave one a special place long before it was used in arithmetic.
Creation from a single beginning
Many creation stories start with one undivided thing, though they describe it in very different terms.
- In Hesiod’s Theogony, a Greek poem usually dated to around 700 BCE, the first thing to exist is Chaos, often understood as a gap or void from which Earth and other powers later arise.
- In Egyptian accounts, the world emerges from Nun, the dark primeval water, and in some versions a single creator such as Atum appears on a mound and brings other gods into being. The nine gods that result form the group known as the Egyptian Ennead.
- In the Norse tradition recorded in medieval Iceland, the world takes shape from the empty space called Ginnungagap, and the first beings are formed from the meeting of ice and fire. The cosmos that results is later pictured as the Nine Worlds around the world tree.
- In Chinese tradition, the Daodejing includes the line often translated as “the Dao gives birth to one, one gives birth to two, two gives birth to three, and three gives birth to the ten thousand things”. The ordering from unity to multiplicity is explicit, and it is one of the clearest statements of the idea in any tradition. It is also linked with the concept of yin and yang, which arises as the one divides.
- In a later Chinese tale, the giant Pangu is born inside a cosmic egg and separates sky from earth. The story is recorded in sources from around the third century CE or later, so it should be treated as a later development in the mythology.
These stories are not copies of one another. What they share is a pattern: a single thing, a division, then the many. The pattern is natural, because it matches the way we think about the growth of a family, a plant or a city, but it is a pattern in human storytelling and not a discovery about the cosmos.
The One in Indian thought
In the Vedic tradition, one hymn of the Rigveda contains a famous line that truth is one while the wise speak of it in many ways. Later Upanishadic texts develop the idea of Brahman as the single underlying reality, with the many things of experience understood as expressions or appearances of it. Schools of Indian philosophy later disagreed sharply about how to understand this unity, so it would be wrong to treat “the Indian view” as a single position. The tradition illustrates that oneness can mean very different things: a single creator, a single substance, or a single truth.
One god: the history of monotheism
The most influential form of the idea in world history is the belief in a single god. Its development was gradual and is still debated.
The Hebrew Bible contains the declaration known as the Shema, which in many translations says that the Lord is one. Scholars discuss whether early Israelite religion first recognised many gods but worshipped one, and when a stricter claim that only one god exists took shape. The terms used for these stages are monolatry or henotheism for worship of one among many, and monotheism for the exclusive claim. The biblical creation story, organised around the seven days of creation, is told as the act of one god from the start.
Other traditions arrived at a single god by different routes. Zoroastrian teaching centres on Ahura Mazda, and Islam’s central principle, tawhid, stresses the oneness of God. Christianity inherited the Jewish insistence on one God and developed what later became the Trinity doctrine, an attempt to reconcile threeness with oneness.
A frequently cited earlier case is Egypt under Akhenaten in the fourteenth century BCE, who promoted the worship of the sun disc Aten. Historians disagree about whether this was monotheism in the later sense or an intense focus on one deity within a wider religion. It did not last beyond his reign.
One in philosophy: the Neoplatonic One
In the third century CE, the philosopher Plotinus described reality as flowing from “the One”, a source beyond description and beyond being, from which intellect and soul emanate. His thought influenced Christian, Jewish and Islamic writers for centuries, and it shows how a number-word became a technical name for the ultimate source. Earlier Greek thinkers such as Parmenides argued that what truly exists is one and unchanging, which shaped the debate about unity and plurality that continued for centuries.
Folk motifs of the single
Folklore reflects the same fascination with the single in smaller ways. Figures defined by having just one of something recur: the one-eyed Cyclopes of Greek story, and the Norse god Odin, who is said to have given up an eye for wisdom. The only child, the sole survivor and the one chosen hero are common story types. Modern ideas about uniqueness and rank, such as those behind the way we treat number one in culture, grow from a similar instinct to place special weight on the single item.
Why the idea endures
There are a few reasons why one holds this place in so many traditions.
- It gives an explanation a stopping point: asking what came before the first thing seems to lead nowhere.
- It offers reassurance that the world is ordered and not random.
- It is easy to state, and it is easy to build on.
At the same time, the history shows that “one” never meant a single thing. It could mean the first in a series, a creator, a substance, a truth or a unity of many parts. Reading a tradition well means asking which of these it intended, and avoiding the temptation to read modern ideas into ancient words.