Thought Finds a World and Creates One Also

In 1763 James Boswell told Samuel Johnson that Bishop Berkeley's argument, that matter does not exist apart from the mind that perceives it, could not be refuted. Johnson kicked a large stone until his foot rebounded and said, I refute it thus. The scene has been told for two and a half centuries because it captures a feeling that everyone shares, that the world is there whether or not anybody thinks about it. The topic adds a second claim to that feeling. Thought not only finds a world, it also creates one, and the essay asks how both can be true of the same mind.

The finding is the easier half to defend. Natural science rests on the assumption that there is a reality to be found and that thinking can reach it. Newton found the laws that govern falling bodies, and his equations predicted the return of comets and the existence of an unseen planet before anyone saw it. In 1846 astronomers pointed a telescope at the spot where calculations said Neptune ought to be and found it. The planet had been there for billions of years, and thought had only caught up with it. The same is true of the structure of DNA, the circulation of the blood and the existence of the bacteria that cause disease.

The creating is the more surprising half, and it is large. Money is a bundle of shared beliefs, since a banknote is worth something only because enough people think so. A nation is, in Benedict Anderson's phrase, an imagined community, held together by newspapers, flags and stories that allow millions of strangers to feel that they belong to one another. The Constitution of India begins with the words We, the people, and by being adopted it created a Republic that had not existed the day before. A corporation, a court and a university are all inventions of thought, and none of them can be found in the way a mountain can.

Philosophers have given careful accounts of how the two halves fit. Immanuel Kant argued that the mind does not passively receive the world but organises experience through concepts such as space, time and cause, so that the world we know is partly shaped by the structure of the knower. Indian thought has its own version. The Advaita school holds that the everyday world is a construction laid over a deeper unity, the work of maya, while the Yogachara Buddhists argued that what we call objects are patterns of consciousness. On such views the line between finding and creating becomes thin. Every act of finding already involves the mind's contribution.

Every act of finding already involves the mind's contribution.

Mathematics poses the puzzle in its sharpest form. G. H. Hardy believed that mathematical truths exist independently and that the mathematician is a kind of explorer who reports what he sees. Others hold that mathematics is a human invention, a language that we have built and could have built differently. Srinivasa Ramanujan, who produced extraordinary formulas with little formal training, said that the goddess Namagiri revealed them to him in dreams. Whether he found them or made them, he could not explain, and no one since has been able to settle the question.

A cautious reader will point out that the two halves are not equals. Creation is constrained by what is found. The Tacoma Narrows Bridge in Washington State, designed with a graceful and slender profile, twisted itself apart in a moderate wind in 1940, only months after it opened. The designers had imagined a bridge that did not take full account of how air moves around a deck, and reality corrected them. Trofim Lysenko's theories in Soviet biology created a world in which acquired traits were inherited and in which wheat could be trained to grow in the cold, and the harvests that followed showed how little the world cared for the theory. Thought can build whatever it likes in the realm of imagination, but anything that is meant to stand in the real world has to be consistent with it.

The reverse also holds. What is found is constrained by what the mind is ready to look for. Astronomers did not find Neptune by accident. They found it because Newton's creation, his theory of gravity, told them where to look. The microscope revealed microbes only after the idea of germs made them worth seeking. Discoveries often follow inventions of concept, and the two activities feed one another in a loop where each begins by borrowing from the other.

Everyday life offers smaller proofs of the same duality. A cook who invents a dish is creating, yet the dish works only because of chemistry that was already there. An architect imagines a building that has never existed and then must meet the stubborn demands of gravity, cement and the monsoon. A teacher who coins a new way of explaining a theorem has made something, but she has made it out of material that her students' minds already hold. In each case thought begins with what is given and ends with something that was not.

Perhaps this loop explains why the topic seems true. Human beings live partly in a world that was there before them and partly in one that they added, and the addition has become so large that it sometimes hides the first. A child born in a modern city may meet more of the human made world than the natural one, and she may take the nation, the market and the school to be as fixed as the rivers. Learning to tell the two apart is a form of wisdom, since what has been made can be remade and what has been found cannot.

How much of the world is of each kind remains unsettled. Johnson's foot hurt, and Berkeley might have replied that pain, too, is an idea. The best that can be said is that thought has never managed to find a world without making a little of it in the process, nor to make one without finding that something resisted. It is unclear whether those two activities are really distinct, or whether they are names that the mind gives to the same act when it looks at it from two sides.