I mentioned in the previous series that naturalism was a prominent position in the free will debate. But what is naturalism. Naturalism is the rejection of the possibility of “first philosophy”. This has implications for both what exists and how we know. Naturalism is not atheism, a religion, nor is it humanism. It is a philosophical belief about how we understand the world.
First philosophy is any philosophical activity that science cannot speak about. Aristotle uses that phrase to describe what most properly belongs to philosophy. In his terms, a discussion of being as being is first philosophy. In our terms, a discussion of things as things is first philosophy. This means that substance theory and any immediate implications are all a part of first philosophy. This includes a discussion of how we know in general, logic, explanation and substance. Second philosophy is that philosophy that depends on our experience of things in the world. Philosophy of science, of language and of politics is of this kind.
Naturalism claims that first philosophy is impossible. There appears to be no common reason why first philosophy is rejected. Some reject it because they believe that substance theory is false. Others reject it because they value science highly and wish to believe that they can learn everything by means of science. Still others reject it because they have not examined or are not aware of any first philosophy. Finally, there are a number of people who claim to have arguments of various kinds against first philosophy.
Naturalism is not atheism or religion. It is not atheism because it is possible to believe in God and in naturalism. It is even possible to believe that God has revealed himself in history as long as the historical evidence supports that claim. What is not possible is to believe that you have knowledge of God that cannot be supported by scientific considerations. Since all traditional theologies do claim this, it is not possible to be a traditional believer and a believer in naturalism. On the other hand, almost all atheists have been naturalists. Naturalism is not religion because it says nothing about what we ought to value. Without saying what is good, it cannot be a religion.
Naturalism is not humanism because humanism is both religious and separate. Humanists believe that human beings are valuable. They also believe that the works of human beings are valuable. Humanism includes the further understanding that human beings are the most valuable things in the universe. Finally, it claims that only the universe ought to be considered in assignments of value. This implies that human beings are of ultimate value. This is the reason that naturalism is a religion. Naturalism does not make these claims and cannot be considered a religion. Humanists are almost always naturalists though, and most of them are atheists as well. Some humanists were not though, especially in the past. Some naturalists believed that God is what made humans valuable, and they fought to increase the perception of that value in their situation.