Looking at Stephen Crane's "The Open Boat," explain a significant idea or stylistic element that exemplifies his naturalistic perspective (a feature denoted by one of these three keywords, Materialistic, Pessimistic and Deterministic) and illustrate by referring to specific passage in the story. Then point to/explain a passage in the story that illustrates Crane's positive view of our human response to the cold, impersonal universe posited by naturalism.

Right from the start of Stephen Crane’s short story “The Open Boat” (first published in 1897 and based on the author’s experience in a shipwreck), we are clearly reading about a struggle between man and nature.
Naturalist philosophy suggests that it is natural laws, rather than supernatural or spiritual ones, that govern the structure and behavior of the universe. Similarly, naturalism in literature studies characters in relation to their surroundings, usually showing nature as an indifferent force that governs human life. George Becker famously described naturalism's philosophical framework as "pessimistic materialistic determinism,” hence the importance of these three terms in discussing the theme.
Throughout the story we find numerous descriptions of the sea as a force that is separate to, and unaffected by, the men who are fighting for their lives aboard a small boat. The waves are a force that the boat has to contend with and are described, for example, as “most wrongfully and barbarously abrupt and tall, and each froth-top was a problem in small boat navigation.” The power of the waves is something the men have to fight against together, without feeling like they are making any progress, and with little understanding of what might still be to come. Likewise, when it starts to get light out they see the effects on the waves but are not fully aware of what is happening: “the process of the breaking day was unknown to them. They were aware only of this effect upon the color of the waves that rolled toward them.” That is, they understand nature only is as much as it directly, physically affects their line of sight, without knowing the bigger picture. They understand what they can see of the material world around them and don't fully comprehend what is behind it.
As well as the descriptions of the waves and the state of the sea, the passage about the wind-tower clearly reveals the naturalistic perspective. Note how it is described as “a giant, standing with its back to the plight of the ants," and how to the correspondent it represents

the serenity of nature amid the struggles of the individual—nature in the wind, and nature in the vision of men. She did not seem cruel to him, nor beneficent, nor treacherous, nor wise. But she was indifferent, flatly indifferent.

While in much of the story the sea, representing nature, is described as if it is full of emotion and anger, here there is a realization that nature is actually indifferent to their struggles. The shore is similarly described as being indifferent to the men who are approaching it, desperately trying to save their own lives. Although it is calmer and less furious than the sea, the correspondent notices “a certain immovable quality to a shore." When the correspondent is caught by a wave and suddenly able to make progress towards the shore, he considers it a “miracle of the sea." The use of the miracle, with its normally religious and spiritual connotations, stands out here as evidence that the character has gained an understanding of the natural laws, of how the sea works, and of the force of nature in and of itself:

A large wave caught him and flung him with ease and supreme speed completely over the boat and far beyond it. It struck him even then as an event in gymnastics, and a true miracle of the sea.

Various passages could be selected to discuss Crane's positive view of the human response to the cold, impersonal universe posited by naturalism. Throughout the story the four men in the boat work together to try to save themselves: they work as a team, giving each other encouragement and hope. The simple act of sharing the experience and providing a commentary on it to each other helps to make sense of their difficult circumstances, even if they are arguing. This sense of being connected to each other is emphasized a few times, for example when they share the cigars, and in the following passage:

It would be difficult to describe the subtle brotherhood of men that was here established on the seas. No one said that it was so. No one mentioned it. But it dwelt in the boat, and each man felt it warm him. They were a captain, an oiler, a cook, and a correspondent, and they were friends.

The way they help each other to get to shore is another example of a positive human response to the indifferent universe, and the help the people on shore offer them is yet another. This implies that while nature is indifferent, people are not, and can, indeed must, support each other through the challenges they face. Furthermore, as the last line tells us, the characters become the "interpreters" of the sea, and accordingly of nature and life in general.