Philosophy › Before Socrates & the first sages › The Presocratic philosophers
What is ultimately real?
first asked c. 585 BC· Big question· Reality, mind & God
Mostly agreedGood evidence; some details uncertain.
The oldest question in Western philosophy: beneath appearances, what is the world really made of, and does it truly change?
See it on the Philosophy map →The idea
This is the core of metaphysics, a name from an editor's title for Aristotle's book 'after the Physics'. Early Greek answers fall into two camps. Some named a stuff: water, air, fire, or atoms. Others named a structure: number for Pythagoras, unchanging Being for Parmenides, later Plato's Forms. India ran a parallel debate: one eternal reality (Brahman) or constant change with no fixed core (Buddhism). Modern physics continues it with particles, fields and information.
Why it matters
Every later system, religious or scientific, starts from some answer to it, and it is where testing answers by argument began.
Where it comes from
Aristotle's Metaphysics, Book 1 (c. 350 BC), surveys earlier answers. Often called the first history of philosophy, it is the source of much of what we know about the Presocratics.
Still debated
Still open: is reality ultimately matter, mind, mathematical structure, or something else? Physicists still disagree about what quantum theory says exists.
Connections (4)
▸What is ultimately real? was first answered by Thales of MiletusMostly agreed
The connection
The question of what lies beneath appearances got its first recorded Greek answer from Thales: water. The answer was soon dropped, but its form, one natural principle (arche, 'origin') explaining everything, framed every later attempt.
When and how
Miletus, Ionia, early 6th century BC.
How sure are we?
Aristotle's Metaphysics reports the water claim and offers reasons for it, while admitting the reasons are his own guess.
Debates and open questions
'First' is doubtful: Upanishadic sages in India asked about ultimate reality around the same time, and little is known of Greek thought before Thales.
▸The Presocratic philosophers first posed What is ultimately real?Mostly agreed
The connection
The Presocratics turned a mythic question, where the world came from, into a philosophical one: what is it made of, and how can it change? Over two centuries they tested answers against each other, from water to atoms, building the field later called metaphysics.
When and how
Greek cities of Ionia and southern Italy, about 585–400 BC.
How sure are we?
Aristotle's survey of his predecessors and fragments preserved by later writers show the debate developing step by step.
Debates and open questions
'First posed' is Greek-centered: the Upanishads asked a similar question in India in the same centuries, apparently independently.
▸Pythagoras and the Pythagoreans answered "number" to What is ultimately real?Mostly agreed
The connection
Where the Milesians named a stuff, Pythagoras named a structure: number and ratio. Because musical harmonies and shapes follow numerical rules, Pythagoreans claimed all things are, or imitate, numbers. This shifted the question from matter to form, a step Plato took further.
When and how
Croton, southern Italy, from about 530 BC, developed by later Pythagoreans such as Philolaus in the 5th century BC.
How sure are we?
Aristotle's Metaphysics reports that the Pythagoreans held 'the principles of mathematics are the principles of all things.'
Debates and open questions
Whether this was Pythagoras' own view or that of later followers like Philolaus is unclear.
▸Democritus and atomism gave a materialist answer to What is ultimately real?Mostly agreed
The connection
Democritus answered that only atoms and void are real; everything else, from color to taste, is how atoms affect our senses. It was the first fully materialist answer: no gods, purposes or minds at the base of reality, only matter in motion.
When and how
Abdera, northern Greece, late 5th century BC.
How sure are we?
His fragment 'By convention sweet, by convention bitter... in reality atoms and void' is quoted by Sextus Empiricus.
Debates and open questions
Sources suggest he thought the soul was atoms too, yet his ethics seem to assume real choice; how he squared the two is still discussed.