It is incumbent on the naturalist to acquire, from all sources – books, people, direct experience – all the knowledge indispensable to the content of his novel: as Zola wrote, ‘Take what you know as a starting-point, firmly establish the terrain on which you'll be working.’ Only from such a foundation can a novelist exercise his true creative function. How thorough, how systematic and how impartial was Zola in acquiring this knowledge? Our first answer, on the evidence available, is simple: he was not impartial, only partly systematic and his thoroughness was far from scholarly. To counteract such deficiencies, it must be added that he had two outstanding gifts: a genius for noting detail and a powerful creative imagination that could dispense with scholarly thoroughness. As far as knowledge of the peasantry was concerned, he had also a great number of excellent cards in his hand. He had grown up in the provinces, having spent his childhood in Aix-en-Provence. His mother came from a country family settled on the borders of Beauce and Zola speaks of listening avidly to his grandfather's conversation about this region – a factor that may well have weighed with him in his final choice of scene for the novel, after he had rejected certain other parts, such as Brittany, which he described as ‘too dismal’. With hindsight, however, we can see how Beauce exactly fitted his bill, with respect to covering as broadly typical a canvas of peasant life as possible and suggesting the general through the particular. Quite apart from its convenient proximity to Paris, Zola found, when he went there for a few days in May 1886 with his plans for the novel already well advanced, precisely what he had hoped for: a smallish village beside a river (Romilly, which became Rognes in the novel), close to a market town (Cloyes in the novel but with similarities to Châteaudun) in which he could set up his middle-class characters, such as a doctor, a veterinary surgeon and a tax-inspector (taxes are very important for smallholders) as well as magistrates and law courts (for the law also plays a big role in La Terre). In Beauce there was a wide variety of farmers – large ones, some of them absentee landlords, struggling share-croppers, tenant farmers and peasants, smallholders scratching a laborious living, sometimes from a couple of acres or less of land – and many types of farming – sheep-rearing, small dairy-farming, forage crops and, most important, wheat, the very staff of life, for Beauce was the vast granary of France. There was another crop, smaller in extent but an equally important pillar of French society: the grape. So we find Bread and Wine almost as two protagonists of the novel. The latter in particular provides a lot of good, clean (or at least, not very dirty) fun in the novel: no reader can fail to be fascinated by the chapter devoted to the grape-picking scenes, when the laxative effect of eating too many grapes causes as many petticoats to be lifted as does, later on, for different reasons, the fuddling effect of drinking their juice. Chartres was also near by and useful to Zola not, oddly enough, for its superb cathedral but because it was large and, with its garrison, busy enough to support a brothel or two, which Zola reconnoitred during his visit. Zola's determination to make the novel not unrelievably gloomy is shown, incidentally, by his description of the Beauceron as ‘gay’, hardly the impression left by a first quick reading of the novel, despite the many moments of rather coarse fun.

Zola had already had far more direct and prolonged contact with French country manners and customs before his brief Beauce trip, although his notes from that trip show much acute and relevant observation. In 1877, following the resounding success of L'Assommoir, he had bought a large house in Médan, a village of less than 200 inhabitants, near Paris but not yet engulfed in the suburbs of the capital. He was henceforth to spend up to six months or more there every year. In 1881 he became for a short while (like a number of the characters of La Terre) a municipal councillor, although frequently an absentee one. There were farmers on the council and it is interesting to know that during his tenure of office there arose, as in La Terre, a question of building a new road and compensating owners for their expropriated land. Zola speaks of the secretiveness and suspicion of the local peasantry and of having as a result to resort to culling information and gossip from his servants. In his preliminary plans, we even find him using one or two local names for his characters.

All in all, therefore, his direct knowledge of French country life was not inconsiderable and probably superior to that of the background of any of his other novels in the series. His documentation from secondary sources is not easy to evaluate. He certainly consulted, if only cursorily, three or four general works on the history of French agriculture and rural population, one of which provided the basis for the long account of the French peasant through the ages (the symbolic Jacques Bonhomme) that occupies such an important position towards the end of the first part of the novel and is clearly intended to place his characters in their proper social, economic and psychological perspective. But it is significant that the work shown by his notes to have most impressed him was a chapter from the very jaundiced Pensées, published in 1886, of an Abbé Roux, concerning his parishioners in a little village in the Corrèze. The similarities between Roux's peasants and Zola's are striking: they are tough, harsh and ungrateful, concerned solely with their own short-term interest, understanding only coercion and thus kowtowing to any established authority, superstitious, barely Christian though perhaps deists, childish, deceitful, stoical, mean and greedy (if someone else is paying): in a word, completely self-centred. Such nasty characteristics are understandable in a context of unremitting toil and grinding poverty. Roux's influence is significant, first because it is living source material about aspects of character – already the very stuff of a novel – and secondly because his disabused opinions chime in completely with Zola's temperament, for we must not forget that, despite his insistence on documentation, Zola defined the work of art as un coin de la création vu à travers un tempérament.

There remained one further type of source for the indefatigable Zola: direct discussion, through personal contact and correspondence. One of his important sources here was an interview which he engineered with the leading French socialist of the time, Jules Guesde, who enlightened him on many matters that recur constantly in the novel: the dangers inherent in the French system of inheritance, which led to ever-increasing subdivision of the land; the threat of imports of wheat and meat from the vast prairies of North America, undercutting the French market; the reluctance of the French peasant, because of conservatism, lack of capital or the poor profitability of his small plot, to embark on modern methods; in general, the precariousness of the peasants' lot and the miserable rewards for their endless toil. All these are constant threads throughout La Terre and there are at least three exponents of left-wing ideas in the novel: the republican ‘Jesus Christ’, still fired by the ideals of the 1848 Revolution; his buddy, the extremist Canon; and the frustrated, bullying schoolmaster who reveals himself at the end as the most anarchistic of all. Zola is obviously determined to offer not only an historical perspective but glimpses of much broader problems that give an important extra dimension to La Terre, absent from many others of the cycle: a sense not only of the past but also of the future, giving an impression of timelessness in human affairs and matching the perennity of natural phenomena.

Not that Zola was unaware of the importance of le petit fait vrai to lend verisimilitude. Both his earliest notes for the novel and his observations from his trip to Beauce deal with just such petty yet indispensable details: peasants coming out with their lamps to inspect the damage after a hailstorm; a woman and a cow giving birth simultaneously; a father chasing a wayward daughter with his whip; the colour and texture of the soil; the changing light over the plain: all most important to ensure concreteness and vividness.