The Number One

Most sacred numbers are counted: seven days, twelve tribes, five prayers. One is different. When a tradition calls something one, it usually means more than a quantity. It means that the thing is whole, undivided, without rival and without parts. That is why one has become the number of God in the great monotheistic religions, and the number of the first source of everything in many philosophies.

In Judaism the classic statement is the Shema, from the Book of Deuteronomy: ‘Hear, O Israel, the Lord our God, the Lord is one.’ Observant Jews recite it every morning and evening, children learn it early, and tradition holds that it should be the last words a person speaks before death. In the twelfth century Maimonides listed God’s unity among his thirteen principles of faith, and insisted that this oneness is unlike any other: not one of a kind, not one made of parts, but simply one.

Christianity inherited the Shema, which Jesus quotes in the Gospel of Mark as the first of the commandments. The Nicene Creed begins ‘We believe in one God’. Christians hold that the doctrine of the Trinity does not make three gods: the Father, the Son and the Holy Spirit are described as three persons sharing one divine being. Jewish and Muslim critics have often disputed whether this is consistent with strict oneness, a debate that runs through centuries of theology.

In Islam the oneness of God, tawhidtawhid The oneness of God, the central teaching of Islam. Glossary, is the foundation of all belief. The first half of the declaration of faith says that there is no god but God, and Sura 112 of the Qur’an, one of the shortest, sums it up: ‘Say: He is God, One; God, the Eternal; He did not beget, nor was He begotten; and there is none like Him.’ Muslims often say this sura is worth a third of the Qur’an. The opposite of tawhid is shirk, giving God a partner, which Islamic teaching regards as the one sin God does not forgive if a person dies unrepentant.

Sikhism makes the number visible. The Guru Granth Sahib, the Sikh scripture, opens with Ik Onkar: the Gurmukhi numeral 1 joined to a sign for Onkar, a name of God. Guru Nanak, the first Guru (1469–1539), placed it at the start of the Mul Mantar, the root statement of belief, and it now appears on gurdwaras, flags and jewellery. The Bahá’í faith, founded in nineteenth-century Iran, extends the idea outwards, teaching the oneness of God, the oneness of religion and the oneness of humanity.

Monotheism did not appear fully formed. Biblical scholars generally see in ancient Israel a gradual change from the worship of a national god among other gods to the claim that only one God exists at all. Some of the clearest statements of that claim, such as ‘I am the Lord, and there is no other’, come from the part of Isaiah usually dated to the sixth century BCE, around the time of the Babylonian exile. Earlier, in fourteenth-century BCE Egypt, the pharaoh Akhenaten had promoted the sun disc Aten above all other gods, but his reform was erased after his death and has no proven link with Israel.

Greek thought arrived at oneness by another road. Early philosophers asked what single principle lay behind the changing world: water, air, number or being. The Pythagoreans called the unit the monad and treated it as the origin of all numbers rather than a number itself; for Greek mathematicians, number meant a plurality, and one was what you measured it with. Parmenides argued that true being must be one and unchanging.

The most influential version came from Plotinus, a philosopher of the third century CE. He described the One as perfectly simple, beyond thought and description, the source from which mind, soul and finally the material world flow out like light from the sun. The soul’s highest goal was to turn back and be united with it. This picture deeply shaped Christian writers such as Pseudo-Dionysius, Jewish philosophers and Muslim thinkers such as al-Farabi, and gave mystics in all three faiths a language for union with God.

Eastern traditions speak of oneness too, though often in a different key. The Rigveda says ‘Truth is one; the wise call it by many names’, and the Chandogya Upanishad describes the first reality as ‘one only, without a second’. Advaita Vedanta, the school associated with Shankara, teaches that the self and Brahman are not two. The Daodejing, by contrast, places one second: ‘The Dao gives birth to one, one gives birth to two, two gives birth to three, three gives birth to the ten thousand things.’ The Dao itself is nameless and comes before number.

Oneness remains a living theme. Jews still cover their eyes when reciting the first line of the Shema, and the verse is written inside the mezuzah fixed to doorposts. Muslims raise the index finger during prayer as a sign of tawhid, and the same gesture has become a widely recognised sign of faith. Ik Onkar is among the most familiar Sikh symbols worldwide.

The idea of a single reality behind many forms also appears in modern conversations between religions. Some take the Rigveda’s ‘many names’ as a basis for respect between faiths; others insist that the differences between the traditions’ ideas of the One matter as much as the similarities. Either way, the smallest number carries some of the largest claims in religious history.