⁂ Concepts · Being · No. 6
Form

A reef knot: the same knot in rope, wire or suture.

Form

The organising structure that makes something what it is, as distinct from the material it is made of.

Theme
Being and reality
Tradition
Greek
Term
εἶδος · eidos
Term fixed
c. 380 BC

In plain terms

The same shape can be made out of anything. A spiral is a spiral in stone, in wire, in a shell or drawn on paper, and nothing about the material is doing the work. What is common to all of them is the arrangement.

Form is the name for that arrangement, considered as the thing that matters. It is why a house is not a heap of the same bricks, and why melting a statue destroys the statue while conserving every gram of the bronze.

The question philosophy adds is where the form is. Is it in the thing, as its organisation? Or does it exist in its own right, with individual things being approximations of it? A great deal follows from the answer, including whether mathematics is a discovery.

As a philosopher would put it

For Plato the Forms are separate, eternal and fully real; particulars participate in them and fall short, and knowledge is of the Form rather than of any instance. Aristotle rejects the separation - form exists only as the form of something - and pairs it with matter in hylomorphism: a bronze sphere is bronze arranged sphere-wise, and neither half exists alone.

The form is what a definition states, what makes a thing a member of its kind, and in living things it is the soul: not an occupant of the body but the organisation that makes this matter a functioning organism.

The medieval argument about universals is downstream of this, and so is the modern one about mathematical structure. Where Plato's separation is revived, mathematics is discovered; where Aristotle's is followed, it is abstracted; where the nominalists win, forms are names and there is nothing there to find.

Where you meet it

A reef knot is the same knot in hemp rope, surgical suture, electrical cable or a shoelace. Sailors, surgeons and climbers all use it and all describe it the same way, and mathematicians have a formal classification of knots in which it has a place independent of anything it might be tied in.

The classification is not about materials at all. Two knots are the same if one can be deformed into the other without cutting, which means a knot is a pattern of crossings and nothing else. Tie it in wire and you have added weight, stiffness and conductivity, and changed nothing that makes it that knot.

Which leaves the question the argument turns on. The reef knot has properties nobody chose and some nobody expected - it slips under a sideways load, which is why climbers avoid it. That property was not put there by anyone. It was found.

What is actually disputed

Whether forms are anything over and above the things that have them.

Platonists hold that they exist independently, on the grounds that a form has features no instance exhibits perfectly and that mathematics behaves like discovery rather than invention. Aristotelians hold that this multiplies entities pointlessly and that a form separated from everything it forms is doing no work. Nominalists deny both: there are similar particulars and a shared name, and nothing further.

The argument is unsettled because each position pays somewhere. Platonism owes an account of how abstract objects relate to concrete ones. Aristotelianism struggles with forms that have no instances. Nominalism has to explain why classifications succeed at predicting - why the world lets itself be sorted at all.

Commonly confused with

  • Essence c. 330 BC Essence is what makes a thing the kind of thing it is; form is the structure that does it. In Aristotle they nearly coincide, and the tradition after him keeps them apart.

Defined against

  • Matter The oldest pair in the analysis of things, and neither half of it exists on its own

Philosophers

  • Plato Forms as separate and fully real
  • Aristotle Form as the organisation of matter, not apart from it
  • William of Ockham Neither - only particulars and the names we give them
  • Duns Scotus A common nature in things, less than universal and more than a name
  • Plotinus Forms in the divine intellect, which is how Platonism reaches the Middle Ages

Works

  • Phaedo Where the Forms are argued for
  • Republic The Form of the Good, and the divided line
  • Metaphysics Form and matter as inseparable
  • Summa Logicae Ockham's case that universals are signs
  • Enneads The Neoplatonic transmission

Schools

Related concepts

Matter c. 330 BC · Essence c. 330 BC · Universals c. 380 BC · Substance c. 330 BC · Potentiality c. 330 BC

Plato's Forms stand apart from the things that share in them; Aristotle keeps the term and brings it back into the thing, which is the disagreement the whole tradition inherits.