What Does the World Afford?: IV. For Whom?

A branch affords perching.

But for whom?

The question sounds obvious until we notice what it does.

The branch does not afford perching in itself. Nor does it afford it to some generic creature called an "observer".

It affords perching to a being with the appropriate capacities.

A sparrow can perch on the branch.

A rhinoceros cannot.

The difference is not in the branch alone, and it is not in the creature alone.

It lies in the relation between them.

This may seem like a small point. It is not.

For it means that the world does not present the same field of possibilities to every form of life.

A tree is not simply a tree from every point of view.

To a bird, it may be a place to perch, nest, shelter or find food.

To a climbing animal, it may be a route through the forest.

To a fungus, it may be a substrate.

To a human, it may be timber, shade, scenery, shelter—or simply something to walk around.

None of these descriptions has to be the true meaning of the tree.

They are possibilities arising from different relations between the tree and different forms of organisation.

This is why affordances should not be confused with perspectives.

A perspective is something an observer has.

An affordance is something that can happen between a being and its environment.

The distinction matters because an organism does not first construct a picture of the world and then decide what to do with it.

Its very organisation already places it in a field of possibilities.

A bird has wings, a particular body weight, a particular visual system, a particular mode of movement. These are not merely properties it possesses alongside an otherwise neutral environment. Together with its history and value organisation, they shape the kinds of relations it can enter into.

The bird's world is therefore not simply the same world, seen differently.

It is, in an important sense, a different field of possibilities.

This becomes especially interesting when we turn to plants.

A plant does not have legs, wings or hands. Its possibilities are organised around growth, attachment, absorption, reproduction and chemical exchange. Light, water, gravity and neighbouring organisms therefore enter into its existence in ways radically different from ours.

We should be careful here.

It would be easy to say that the plant "perceives" these things as possibilities, or that they "mean" something to it.

But we have not established that.

We have established something simpler.

The plant is organised in such a way that certain features of its environment make a difference to what it can become and do.

That may be enough.

Indeed, perhaps it is important that it be enough.

For if we make perception or meaning a prerequisite for an affordance, we risk importing human categories into the very phenomenon we are trying to understand.

The plant need not think light in order for light to participate in its growth.

The bird need not formulate branch in order for the branch to participate in its perching.

The organism does not have to represent the possibility for the possibility to be real.

This gives us a rather strange picture of a living world.

There is no single inventory of possibilities waiting to be perceived.

There are overlapping fields of possibility, generated by the meeting of different forms of organisation with the same structured world.

And these fields can overlap in surprising ways.

The branch can support the bird.

The bird can inhabit the branch.

The bird can alter the branch.

The branch can become part of the bird's nest.

The nest can then become part of the bird's reproductive environment.

Possibilities generate new possibilities.

The relation is not between a static organism and a static world.

Both are continually changing through their encounters.

Perhaps, then, asking What does the world afford? is incomplete.

We should ask:

What does the world afford to this being, given what this being is capable of?

And even that may not be quite enough.

For a possibility is not necessarily something an organism recognises.

It may simply be something that its organisation allows the world to do with it—or allows it to do with the world.

That distinction will become important.

Because once we begin to talk about organisms responding to the possibilities their environments afford, we are standing very close to words like perception, information, relevance and meaning.

And we have already seen how easily those words can lead us astray.

Perhaps the first task is to understand how a being can be responsive to a possibility without representing it.

That takes us to a rather unfamiliar place.

A place before meaning.

What Does the World Afford?: III. The World Has Structure

We have said that an affordance is neither a property of a thing nor a projection of an observer.

It is a relation.

But this creates a new problem.

If what a thing affords depends upon what encounters it, might we conclude that the possibilities are entirely supplied by the organism?

The chair affords sitting because we are capable of sitting.

The branch affords perching because the bird is capable of perching.

The wall affords neither sitting nor passage because of what we can do with it.

Perhaps, then, the world is simply raw material for the possibilities that organisms bring with them.

But that won't do.

The world has structure.

A branch has a certain strength. A wall has a certain solidity. A gap has a certain width. A slope has a certain angle. Water flows downhill whether or not anything finds that fact interesting.

These properties constrain what can happen.

We cannot sit on every object.

We cannot walk through every opening.

We cannot fly merely by deciding that the air should support us.

The organism brings capacities to the relation, but it does not bring the whole relation.

This matters because it gives us a useful way of avoiding two opposite mistakes.

The first is to treat affordances as intrinsic properties.

The second is to treat them as subjective projections.

Neither is adequate.

A cliff does not contain a warning.

But neither is its capacity to precipitate a fall something we invent.

The cliff has a structure that makes some interactions possible and others impossible.

The important point is that possibility is not the same thing as meaning.

The cliff's height and gravity constrain what happens to a falling body. They do not communicate a message about what the body ought to do.

The distinction becomes even clearer with organisms.

A plant grows towards light, but the light does not have to mean anything to the plant for its presence to alter the plant's possibilities.

A root encounters a stone and changes direction. The stone does not have to be an obstacle in the semantic sense for the encounter to constrain what the root can do.

Something can therefore be relevant to an organism without being meaningful to it.

This is perhaps the most important distinction we have encountered so far.

For meaning is extraordinarily tempting.

Once we see an organism responding systematically to something in its environment, we are inclined to say that it has detected, interpreted or represented that thing.

Sometimes that may be exactly right.

But it need not be.

A structured world can make a difference to an organism simply because the organism is organised in a way that is sensitive to that structure.

No message is required.

No interpretation is required.

No little observer needs to be sitting inside the organism, reading the world.

There is simply a relation between what the world permits and what the organism can do.

And yet the relation is not passive.

The organism does not merely encounter a collection of fixed physical facts. Its own capacities help determine which possibilities become available.

The same slope is climbable for one creature and impassable for another.

The same temperature is harmless to one organism and fatal to another.

The same chemical substance is nourishment for one organism and poison for another.

The world has structure.

But structure does not come with a single interpretation attached.

Perhaps, then, an affordance is what happens when worldly structure meets organised capacity.

The world supplies neither invitations nor meanings.

It supplies constraints.

The organism supplies neither arbitrary projections nor pure invention.

It supplies capacities.

And between the two, possibilities emerge.

We have therefore moved a little closer to the puzzle.

But there is still a question waiting for us.

If the same world can afford different things to different beings, what makes an organism the kind of being for which a particular possibility exists at all?

What Does the World Afford?: II. A Chair Is Not a Chair

A chair is a chair.

Or so it seems.

It has four legs, a seat, perhaps a back, and a remarkably persistent tendency to turn up whenever we need somewhere to sit.

But what is a chair?

For a human being, it may afford sitting.

For a small child, it may afford climbing.

For someone moving house, it may afford carrying.

For a carpenter, it may afford dismantling.

For someone trying to reach a high shelf, it may afford standing upon.

For a cat, it may afford sleeping.

For fire, eventually, it may afford burning.

None of these possibilities is simply in the chair.

If sitting were an intrinsic property of the object, we would have to explain why the same object can afford so many other activities. Nor can we solve the problem by saying that the chair possesses all these possibilities simultaneously. That merely gives the object a catalogue of affordances, waiting for the appropriate user to arrive.

But the opposite solution is no better.

Perhaps, we might say, the chair has no affordances at all. We simply project them onto it. Sitting is something we imagine; climbing is something the child imagines; sleeping is something the cat somehow supplies.

Yet this goes too far in the other direction.

The chair really does support us.

It has a height, a shape, a weight-bearing capacity and a particular relation to the ground. If it collapses when we sit on it, we don't normally conclude that our projection has failed. We conclude that the chair was unsuitable—or broken.

Something about the object matters.

But it is not enough by itself.

The same physical structure can participate in different possibilities depending on what encounters it.

This is why an affordance is neither a property of the object nor a property of the subject.

It is a relation between them.

And that relation is not arbitrary.

A chair does not afford sitting to a cloud. A brick wall does not afford passage to a human body simply because someone wishes it did. A branch that supports a sparrow may not support a person.

Affordances therefore depend upon capacities as well as structures.

The world supplies constraints.

The organism supplies capacities.

The possibility arises between them.

This is easy to miss because our language encourages us to compress the whole relation into a noun.

We say chair, as though the word named a self-contained thing with a fixed identity.

But perhaps the more revealing question is not:

What is this thing?

but:

What can happen between this thing and something else?

The chair does not cease to be a chair when nobody is sitting on it. But what it affords is not exhausted by what it is considered to be.

Its affordances belong to its relations of possible action.

And this gives us a useful distinction.

A chair can have a physical structure without having a meaning.

It can enter into a relation of possible action without representing that action.

It can afford sitting without saying sit here.

That last distinction will become increasingly important.

For once we notice that a possibility can be real without being a message, we can begin to see how much work we have been asking the concept of meaning to do.

Perhaps the world does not need to mean anything in order to make a difference to what can happen.

Perhaps it is enough that the world has structure, and that living beings have capacities.

The chair, then, is not quite what we thought.

It is not merely an object with properties.

Nor is it a screen onto which organisms project their intentions.

It is a node in a field of possibilities.

And those possibilities do not belong to the chair alone.

They emerge when the chair meets an organised being with particular capacities, histories and ways of responding.

A chair is not a chair, perhaps, because of what it means.

It is a chair because of what it makes possible.

And that leaves us with the next question.

If possibilities arise in the relation between organism and world, how much of the possibility comes from the world itself?

What Does the World Afford?: I. The World Offers No Invitations

A chair invites us to sit.

A doorway invites us to enter.

A path invites us to follow it.

A cliff warns us not to step over the edge.

We say such things without hesitation. And, in ordinary circumstances, there is nothing wrong with saying them.

But the world does not actually issue invitations.

The chair has no intention of being sat upon. The doorway is not asking us to enter. The cliff is not warning us of anything.

Yet something is happening.

The chair is shaped in a way that makes sitting possible. The doorway makes passage possible. The cliff makes falling possible—and, for a creature capable of falling, perhaps makes staying away from its edge a very good idea.

These possibilities are not simply properties of things.

A chair is not intrinsically a sitting possibility. A sufficiently strong chair might be a useful step for one person, a barricade for another, or an obstacle for a small animal. Its possibilities depend upon what encounters it, and upon what that being is capable of doing.

But neither are these possibilities merely inventions of the mind.

The chair really will support a person. The doorway really will permit passage. The cliff really will not permit us to walk through it.

We have therefore arrived at an awkward middle ground.

The possibility belongs neither entirely to the object nor entirely to the observer.

It belongs to a relation.

This is what makes affordances so interesting—and so dangerous.

The word afford seems innocent enough. But once we say that the world affords something, we are tempted to make the world sound as though it were speaking to us. We begin to imagine that things contain invitations, messages or meanings waiting to be perceived.

And then a subtle mistake becomes possible.

We move from:

This makes something possible for this kind of being

to:

This means something to this kind of being.

Those are not the same claim.

A branch may afford perching to a bird without meaning "perch here".

Light may afford a particular kind of growth to a plant without meaning anything to the plant.

A gap may afford passage to one organism and exclusion to another without signifying either possibility.

The world can therefore constrain what is possible without communicating what is possible.

That distinction may seem small.

It isn't.

For once we separate possibility from meaning, we can begin to ask a much more interesting question.

What exactly happens between a structured world and an organised being when one becomes capable of doing something in relation to the other?

Perhaps the world does not invite us anywhere.

Perhaps it does something stranger.

It makes some ways of going possible, and others impossible.

And perhaps meaning begins much later than that.

For now, we should resist the temptation to put it there too soon.

The world offers no invitations.

But it may afford possibilities.

And that is where our trouble begins.