Thomas Hardy's novel Tess of the d'Urbervilles reflects naturalistic themes in both its plot structure and its literary techniques.
Naturalism in literature is not just a literary technique, but a more general ideological or philosophical position about the relationship of people to their external environments. In particular, Naturalism tends to portray character as overwhelmed by circumstance, and the individual's life as to a great degree determined by environment.
In terms of literary style, Tess of the d'Urbervilles reflects the themes of naturalism in the way in which it includes rich details of everyday life, with long, minute descriptions of everyday activities rather than just selected important moments. In setting, it reflects another major theme of Naturalism, namely an emphasis on the lives of people living in poverty and of the lower classes rather than focusing on the upper and middle classes. Finally, it shows Tess (and to a lesser degree Angel) being very much the victims of external circumstances, unable to escape the patterns of life associated with social class and environment. Rather than external factors and coincidences operating in a positive fashion, in Tess of the d'Urbervilles they tend to have negative impacts, grinding characters back down just as it appears that they may be able to escape their fates.