From Bitter Bean to Global Bar: A History of Chocolate
The cacao tree, Theobroma cacao, grows only in the hot, humid belt within about twenty degrees of the equator, and its seeds were being turned into a drink in Central America at least three and a half thousand years ago. Residue found in pottery vessels from what is now Honduras suggests that the earliest users may have been as interested in the sweet pulp surrounding the beans, which ferments readily into a mild alcohol, as in the beans themselves. Only later did people learn to ferment, dry, roast and grind the seeds into a paste. The bitter, frothy beverage that resulted bore little resemblance to the sweet confection sold today; it was often flavoured with chilli, vanilla or maize and whipped to raise a thick head of foam.
Among the Maya and later the Aztecs, cacao was far more than a refreshment. The beans served as a form of money: a document from the sixteenth century records that a rabbit could be bought for a number of beans and a turkey for rather more, and counterfeiters were known to fill empty shells with earth to pass them off as the genuine article. Cacao also carried heavy ritual and symbolic weight. It was consumed at royal feasts, offered to the gods and buried with the dead, and its consumption was in some periods restricted to nobles, warriors and merchants. The Aztecs, who could not grow the tree in their highland heartland, obtained beans as tribute from conquered lowland provinces, which underlined the crop's status as a luxury.
Cacao reached Europe in the sixteenth century in the wake of the Spanish conquest, though its rise was gradual rather than immediate. The bitter drink did not suit European palates until it was sweetened with sugar — itself an expensive import — and warmed rather than served cold. Spain guarded the novelty for several decades, but by the seventeenth century the fashion had spread to the courts and salons of France, Italy and England, where chocolate houses became places to gossip and do business much as coffee houses did. Throughout this period chocolate remained a drink, and a costly one, associated with leisure and privilege. Physicians argued over whether it was a medicine or a vice, prescribing it for some ailments while warning of its supposed dangers.
The transformation of chocolate from an aristocratic drink into an everyday food was the work of the nineteenth century and its machines. In 1828 a Dutch chemist, Coenraad van Houten, patented a press that squeezed much of the fat, or cocoa butter, out of roasted beans, leaving a powder that mixed easily with water. His process also treated the powder with an alkali to soften its flavour, a method still called 'Dutching'. Crucially, the leftover cocoa butter could be recombined with sugar and ground beans to produce a smooth paste that would set into a bar. The British firm Fry's sold one of the first such eating chocolates in 1847, and in the following decades Swiss makers added powdered milk, developed by Henri Nestlé, to create the milder milk chocolate that would come to dominate the market.
As demand soared, production shifted decisively away from the Americas. European powers established cacao plantations in their tropical colonies, and by the early twentieth century the crop had taken firm root in West Africa. Today a handful of countries there, above all Côte d'Ivoire and Ghana, supply the majority of the world's beans, most of them grown not on large estates but on millions of small family farms. This geography contains an irony: the regions that grow cacao consume very little chocolate, while the wealthy countries that consume most of it grow none at all. The bulk of the value added — the grinding, blending and branding — takes place far from the farms, and the price paid to growers for raw beans is a small fraction of the price of the finished bar.
That imbalance lies behind many of the difficulties that trouble the industry today. Farmers dependent on a single crop are exposed to swings in a world price they cannot influence, and low incomes have been linked to deforestation, as growers clear new land to raise output, and to the use of child labour on some farms. A range of certification schemes now promise consumers that the beans in a given bar were produced under fairer or greener conditions, though critics question how rigorously such promises are checked. What is clear is that a product once reserved for Mesoamerican royalty and European aristocrats has become a global commodity whose supply chain stretches, unevenly, across the planet.
Reading Passage 1 has six paragraphs, A–F. Choose the correct heading for each paragraph from the list of headings below. Write the correct number, i–ix, next to each paragraph.
- i Government control of the chocolate trade
- ii From a bitter bean to a foaming drink
- iii The uneven costs of a global treat
- iv How cacao trees are cultivated today
- v More than a drink: money and ceremony
- vi A slow conquest of European tastes
- vii Medical benefits confirmed by modern science
- viii The inventions that turned a drink into a bar
- ix A crop that moved across the world
Do the following statements agree with the information given in Reading Passage 1? Write TRUE if the statement agrees with the information, FALSE if it contradicts it, or NOT GIVEN if there is no information on this.
Complete the sentences below. Choose NO MORE THAN TWO WORDS from the passage for each answer.
Pulling Carbon from the Sky
For decades, the response to climate change focused almost entirely on emitting less: switching to renewable energy, improving efficiency and phasing out coal. That remains the priority. Yet as national pledges have shifted towards 'net zero' — balancing the greenhouse gases a country releases against those it removes — a second idea has moved from the margins to the centre of debate. If some emissions, from aviation, cement-making or agriculture, prove very hard to eliminate, then the only way to reach a genuine balance may be to take an equivalent quantity of carbon dioxide back out of the atmosphere. Trees do this naturally, but the amounts involved are vast, and land is finite. Engineers have therefore begun to ask whether machines can capture carbon dioxide directly, and whether doing so could ever be practical on the scale the problem demands.
Two broad approaches are usually grouped under the label 'carbon capture', and it is important not to confuse them. The older and more mature is capture at the point of emission: fitting a chimney at a power station or factory with equipment that strips carbon dioxide from the exhaust gases before they escape. Because the gas in a flue is relatively concentrated, this is comparatively straightforward, and versions of the technology have operated for years. But it does nothing about emissions that have already occurred, nor about the countless small, scattered sources — vehicles, homes, farms — that have no chimney to fit. The newer and more ambitious approach, direct air capture, tackles this by extracting carbon dioxide from ordinary open air. Since the gas makes up only about four parts in ten thousand of the atmosphere, the task is far harder, rather like trying to remove a specific dye from a swimming pool.
A direct air capture plant typically works by drawing large volumes of air across a chemical that binds to carbon dioxide, either a liquid solution or a solid material laid out on filters. Once the chemical is saturated, it is heated to release the captured gas in pure, concentrated form, ready to be stored or used, and the chemical is then reused. The obstacle is energy. Because carbon dioxide is so dilute in the air, enormous quantities must be moved and the binding agent must be heated repeatedly, all of which consumes power. If that power comes from fossil fuels, the exercise is self-defeating; only when it is drawn from clean sources does the plant remove more carbon than it emits. The first commercial facilities capture only a few thousand tonnes a year, at a cost per tonne many times higher than most industries currently pay to pollute.
Capturing the gas is only half the challenge; it must then be prevented from returning to the air. The most discussed option is to compress it and inject it deep underground into porous rock formations, often the same geological structures that held oil and gas for millions of years. An alternative is to react the carbon dioxide with certain minerals so that it turns, permanently, into solid rock — a slow process in nature that engineers are trying to accelerate. A third route is to put the captured gas to use, in fizzy drinks, greenhouses or synthetic fuels. Critics note, however, that most such uses release the carbon again before long, so that only storage offers a lasting removal. Confidence that buried gas will stay buried, and can be monitored for leaks, is essential if the public is to accept the technology.
The strongest objections to carbon removal are not technical but strategic. Many environmentalists fear a 'moral hazard': the mere promise of a future clean-up, they argue, gives polluters an excuse to keep emitting now, weakening the pressure to make the deep and immediate cuts that matter most. There is also the question of scale. To offset even a modest share of current emissions would require thousands of plants and a colossal amount of clean electricity that could arguably be used to replace fossil fuels directly. Sceptics conclude that money spent on unproven removal would be better invested in wind, solar and insulation. Supporters counter that this poses a false choice: the world will almost certainly miss its targets through emission cuts alone, and will need removal as well, so the technology must be developed now, before it is desperately required.
Where does this leave the ordinary reader trying to judge the claims? The honest answer is that carbon removal is neither the salvation its boldest promoters imply nor the dangerous distraction its critics fear. It is a tool that is real but immature, expensive today and useful chiefly for the fraction of emissions that cannot be eliminated any other way. Its greatest risk is not that it fails to work but that it works just well enough to be used as an excuse. Kept in proportion — as a supplement to rapid decarbonisation rather than a substitute for it — it may yet earn a modest but genuine place in the response to a warming world.
Choose the correct letter, A, B, C or D.
Look at the following statements and the list of approaches below. Match each statement with the correct approach, A–D. NB You may use any letter more than once.
- A Capture at the point of emission
- B Direct air capture
- C Turning the gas into rock with minerals
- D Putting the captured gas to use
Complete the summary below. Choose NO MORE THAN TWO WORDS from the passage for each answer.
Do the following statements agree with the claims of the writer in Reading Passage 2? Write YES if the statement agrees with the claims of the writer, NO if it contradicts them, or NOT GIVEN if it is impossible to say what the writer thinks.
Discovered or Invented? The Puzzle of Mathematical Truth
Ask a mathematician whether the number seven exists and you may get a puzzled look, for the question sounds either trivial or absurd. Yet beneath it lies one of the oldest and least settled disputes in philosophy. Mathematical truths seem to possess a certainty that ordinary facts about the world lack: that a prime number cannot be even and greater than two feels not merely true but necessarily true, in a way that 'water boils at a hundred degrees' does not. Where does this certainty come from? When a mathematician arrives at a new theorem, is she uncovering a fact that was already the case, waiting to be found, or is she constructing something that did not exist until human minds brought it into being? In short, is mathematics discovered or invented? The competing answers reveal deep disagreements about the nature of knowledge itself.
The oldest answer, associated with Plato and still held by many working mathematicians, is that mathematics is discovered. On this view, numbers, sets and geometric forms exist independently of human thought, in an abstract realm outside space and time, and the mathematician's task is to explore that realm much as an astronomer explores the sky. The appeal of this position, known as Platonism or mathematical realism, is considerable. It explains why mathematical truths feel discovered rather than decided: no committee can vote a theorem false, and mathematicians working in different centuries and cultures arrive at the same results. It also fits the phenomenology of research, the strong sense practitioners report that they are bumping up against something independent of themselves, something that resists their wishes and occasionally surprises them with results no one intended.
A further consideration is often marshalled in the realist's favour. The physicist Eugene Wigner famously wrote of the 'unreasonable effectiveness' of mathematics in describing the physical world: abstract structures dreamed up for their own sake, with no application in mind, turn out decades later to describe the behaviour of particles or galaxies with uncanny precision. If mathematics were merely a human invention, a free creation of the mind, why should the universe conform to it so faithfully? For the realist, the answer is that mathematics works because it describes a reality that was there all along, of which the physical world is somehow an expression. Critics reply that we notice the successful applications and quietly forget the vast quantity of mathematics that describes nothing physical whatever.
Yet Platonism faces a formidable objection, one sharpened by the philosopher Paul Benacerraf. If mathematical objects exist outside space and time, then they can have no causal contact with us: they cannot be seen, touched or measured, and cannot affect our brains. How, then, could we ever come to know anything about them? Our best account of knowledge holds that we know about things by interacting with them, directly or through instruments, yet an abstract realm is by definition beyond all such interaction. The realist must therefore explain how beings made of matter could gain reliable knowledge of objects that, on the theory's own terms, can never touch us. No fully satisfying answer has been given, and for many philosophers this gap is reason enough to look elsewhere.
One alternative abandons the abstract realm altogether. According to formalism, mathematics is not about any objects at all but is essentially a game played with symbols according to agreed rules, rather like chess. On this account, to say that a theorem is 'true' is only to say that it can be derived from certain axioms by permitted steps; the symbols need not refer to anything beyond themselves. Formalism, championed in the early twentieth century by David Hilbert, promised to place mathematics on a secure footing by proving that its systems were free of contradiction. That ambition suffered a heavy blow when Kurt Gödel demonstrated that any system rich enough to express arithmetic must contain true statements it cannot prove, and cannot establish its own consistency. If mathematics is only a game, moreover, its uncanny usefulness in physics becomes newly mysterious, for why should an arbitrary game fit the world?
A third tradition treats mathematics as neither discovered nor a mere game, but as constructed by the human mind. For the intuitionists, led by the Dutch mathematician L. E. J. Brouwer, a mathematical object exists only when we have a method for constructing it, and a statement is true only when we can produce a proof of it. This has startling consequences. Intuitionists reject the familiar principle that every statement is either true or false regardless of whether we can decide which, at least where infinite collections are concerned, since we may have no procedure for settling the matter. Much of classical mathematics has to be rebuilt, and some of it abandoned, on this stricter foundation. The reward, its defenders argue, is that mathematics is grounded in something we understand — the activity of the human mind — rather than in a ghostly realm we can never reach.
Where does this leave the original question? Each position captures something the others struggle to explain — the realist the objectivity of mathematics, the formalist its logical structure, the constructivist its dependence on human reasoning — yet each pays a price the others avoid. Some philosophers now suspect that the stark choice between discovery and invention is itself misleading, a false dichotomy imposed by ordinary language on an activity that fits neither category comfortably. Perhaps mathematics is invented in its notation and its choices of which questions to pursue, yet discovered in the results those choices force upon us, so that the mathematician is at once author and explorer. That such a fundamental question remains open, after more than two thousand years, is a reminder that the most familiar of human achievements can also be the least understood.
Reading Passage 3 has seven paragraphs, A–G. Which paragraph contains the following information? Write the correct letter, A–G. NB You may use any letter more than once.
- A Paragraph A
- B Paragraph B
- C Paragraph C
- D Paragraph D
- E Paragraph E
- F Paragraph F
- G Paragraph G
Do the following statements agree with the information given in Reading Passage 3? Write TRUE, FALSE or NOT GIVEN.
Choose the correct letter, A, B, C or D.
Answer the questions below. Choose NO MORE THAN THREE WORDS from the passage for each answer.