Hardy was a naturalist, part of a Darwinist-influenced literary movement at the end of the nineteenth and beginning of the twentieth century that saw nature as indifferent to humankind. He also was a social historian recording the decline of rural life in southwest England, an area he called "Wessex."
Tess herself comes from a poor, rural family and lives her life in a rural setting close to nature. However, being close to nature does not protect her innocence. In her first job away from home, she is raped and impregnated. After her baby dies, she leaves to live and work at a dairy.
Here, nature plays its most important role. The dairy is seemingly an edenic, idyllic place. It simple abundance appear to exist outside of the "threadbare" fashions of the conventional middle class:
Dairyman Crick’s household of maids and men lived on comfortably, placidly, even merrily. Their position was perhaps the happiest of all positions in the social scale, being above the line at which neediness ends, and below the line at which the convenances begin to cramp natural feelings, and the stress of threadbare modishness makes too little of enough.
The heady beauty of nature at the dairy deceives Tess into believing she can find redemption despite her "sin" of having had a child out of wedlock. It leads her to think that Angel Clare is more than a conventional, narrow-minded, middle-class man. Angel, too, is intoxicated by the romantic setting. Both Tess and Angel, for instance, succumb to the heady feeling that they reflect Adam and Eve as they rise in the spring mists to milk the cows. However, Hardy undercuts these romantic notions by alluding to nature's Darwinist indifference:
Another year’s installment of flowers, leaves, nightingales, thrushes, finches, and such ephemeral creatures, took up their positions where only a year ago others had stood in their place when these were nothing more than germs and inorganic particles.
Nature might be beautiful, but it is indifferent, and Tess descends along her tragic path in light of this indifference.