The Universe Next Door: A Basic Worldview Catalog

Naturalism, in essence, says that nature and matter are all that exist. For Sire, naturalism takes us one step further away from Christian theism. Historically, naturalism was the result of a gradual reduction of the idea of God. First, in deism, God’s personality and sustaining providence are denied; in naturalism, the existence of God is denied altogether.

Although none of them denied God’s existence—indeed, all professed theism—such thinkers as René Descartes, John Locke, and Julien de La Mettrie set the stage for naturalism. Descartes conceived of reality as divided between “matter” and “mind.” Naturalists went one step further by declaring that mind itself was merely a “subcategory of mechanistic matter” (56).

Thus, for naturalism the “prime reality is matter; matter exists eternally and is all there is. God does not exist” (57). This makes naturalism essentially a form of materialism. Since nothing can come of nothing, something always had to have existed. Naturalists say that this something was matter, not God or mind.

According to naturalism, the universe is a closed system in which things happen according to unchangeable laws of cause and effect. Nothing from outside the system of nature can change these laws for the simple reason that there is nothing outside the system of nature; nature (consisting of matter acting according to inexorable laws) is all that exists. Human beings are themselves part of this system; they are complex “machines.” Personality is real and important, but it is a product of chemical and physical properties, and thus a function of matter.

At the same time, many naturalists insist that human beings are unique and different from other objects in the universe because they possess such faculties as thought, language, and culture. However, the emergence of these faculties is rooted in purely natural processes such as evolution. Naturalists maintain that, although the nature of human uniqueness is not fully understood, this is simply because science needs to pursue further investigations.

Because human beings are simply made up of matter, death means the extinction of the individual person. The only way for human beings to prolong their existence beyond death is by “living” through their progeny and in terms of their influence and impact on others’ lives.

Naturalist epistemology states that human reason can help us arrive at knowledge of the universe and the world around us. However, some naturalists deny that we can discover truth in itself. Rather, we must be content to “learn to describe what we take to be reality in language that allows us to live successfully in the world” (65); knowledge is thus purely pragmatic.

Sire observes that naturalists typically have agreed with theists on basic moral and ethical questions (although this is changing somewhat in the context of contemporary bioethical issues). However, the metaphysical basis of these questions is very different in each worldview. For the theist, moral values are grounded in God’s nature; for the naturalist, moral values are manmade. Since mind and consciousness only appeared on the scene when human beings did, it follows that the sense of right and wrong did, too. Thus, morality has no transcendent basis but developed out of human beings’ needs and experiences.

This naturalist belief creates a philosophical problem, however, which boils down to the following question: “How does ought derive from is?” (67). In other words, just because something is this way does not mean that it ought to be or should be; therefore, ethically speaking, just because human beings do act in a particular way does not mean that they ought to or that acting in this way is morally right. To solve this problem, naturalists often argue that human survival is the primary ethical value, and that whatever contributes to this is right.

As with their view of nature in general, naturalists view history as “a linear stream of events linked by cause and effect but without an overarching purpose” (70). The reason why the universe and humanity came into being is shrouded in mystery, although naturalists stress the importance of the Big Bang and the theory of evolution as ways to explain the origin of the universe and humanity. Still, naturalists tend to view all these processes as self-activating instead of having been willed by a supreme being or expressing any kind of ultimate purpose. In the end, human beings will die out and history will come to an end.

Naturalists do not agree on a single core commitment, but may choose whatever commitment they or their culture dictates, with an emphasis on “purely secular human flourishing” (73).

Having sketched the theoretical basis of naturalism, Sire devotes the rest of the chapter to discussing two important examples of naturalism in practice: secular humanism and Marxism.

Sire writes that secular humanism is one particular type of humanism. Humanism in general is the attitude that “human beings are of special value; their aspirations, their thoughts, their yearnings are significant” (74). There are and have been humanists who frame their thought within a theistic, Christian perspective. However, secular humanism is “a form of humanism that is completely framed within a naturalistic worldview” (74-75). In the words of Charles Taylor, secular humanism accepts “no final goals beyond human flourishing” in the present, earthly life (74).

Since the middle of the 19th century, Marxism has emerged as an important and influential manifestation of secular humanism. This ideology stems from the ideas of the philosopher Karl Marx, who stated that “man is the supreme being for man” and who theorized a future state in which human needs would be satisfied (76). Marx was influenced by the German philosopher G. W. H. Hegel, who believed that God or “absolute spirit” was being progressively realized in the concrete world by a “dialectical” process. In brief, Hegel’s dialectical approach denotes a historical unfolding whereby opposing and seemingly contradictory forces synthesize into a greater whole, ultimately culminating in the total realization and fulfillment of absolute spirit. Marx combined this doctrine with the materialism of the German philosopher Ludwig Feuerbach, thus interpreting Hegel’s “dialectic” in material terms and without any reference to God or spirit. Marx argued that “since human beings are material, their lives must be understood in terms of the need to work to satisfy their material needs” (77). Marxism was intended as a solution to those needs, interpreting social and class struggle as the impetus that would lead to a better social order.

According to Sire, naturalism is still the dominant worldview in modern educational institutions and intellectual culture generally, including the sciences, although it has been recently challenged by postmodernism and by a resurgence of various types of theism. One reason for naturalism’s durability is that it “gives the impression of being honest and objective” (81), suggesting that it is rooted in science and scholarship. Another reason it is attractive is that it accords human beings the highest place in nature and the ability to make values for themselves and run their lives as they see fit.

However, critics have challenged naturalism, arguing that it is unable to give an adequate explanation of human value and dignity. These doubts, claims Sire, led directly to a form of philosophical despair or pessimism known as nihilism.