During his lifetime, Zola made his presence felt in almost every area of the literary world. He was constantly involved in some type of literary controversy. In one sense, he is best known for his theories and defense of naturalism, and he has aptly been called the father of naturalism.
Many critics fail to make a distinction between "realism" and "naturalism." Certainly, the distinction does not involve a major critical view. Realism might be most simply explained as an attempt to present life with a large degree of verisimilitude. As a movement, realism preceded naturalism, and the latter movement is essentially an attempt to carry the position of the realist to a further degree. Sometimes naturalism is called "stark realism."
The naturalist thought that the realist had not treated all aspects of life and was determined to show everything connected with life. The naturalist also accused the realist of failing to depict things which are unpleasant, ugly, or sordid. Consequently, the naturalist often concentrates to a greater extent on those aspects of life which are of dubious value, and seldom does it depict the higher nature of humanity.
In theory, the naturalist saw humanity trapped by forces which it could not control. Humanity is caught in a hostile universe and there is no chance for it to escape. When humanity realizes its trap or if it attempts to escape, it is usually reduced to the level of an animal. In general, the naturalistic philosophy might be called pessimistic determinism — that is, humans are totally unable to control their own destinies.
With this philosophy, the naturalist will often use the image of humanity trapped in some type of cage or in some type of circumstances which could be symbolically viewed as a net or cage. Then the dominant image will often involve a person as some sort of animal. The naturalist uses this animal imagery to reinforce the position that people cannot control their urges and are ultimately reduced to bestiality. The French Zola and the American Frank Norris are the most famous for their uses of animal imagery to depict the lack of nobility in humanity.
The naturalist, wishing to capture verisimilitude to the nth degree, would often belabor his descriptions. Many times, this type of writer would often continue his description of physical objects far beyond the patience of the reader. Their flaw then is a result of their desire to give an absolutely accurate account of their position, and in doing so, they often became tedious with their laborious descriptions.
Finally, in trying to be completely true to life, the naturalist probably distorted life as much as did the romantic writer. While determined to present the true side of life and therefore concentrating on the ugly and the sordid, the naturalist emphasized this aspect of life to the exclusion of any other aspect. The realist knows that there is the sordid side, but he often presented the pleasant or happy side of life; the naturalist restricted life to the ugly and unpleasant, thereby distorting real life instead of depicting it as accurately as he thought he would.