Naturalism is the idea that only natural laws and forces (as opposed to supernatural ones) operate in the universe. ... it is also known as ontological naturalism, metaphysical naturalism, pure naturalism, philosophical naturalism and antisupernaturalism.*

Naturalism is philosophy. Let's check some statements about naturalism by evolutionist Steven Schafersman who represents mainstream science...

Naturalism implies a unity and lawfulness in nature, a condition in which nature's reality can be objectively understood, without which the pursuit of scientific knowledge would be useless. ... Methodological naturalism is the adoption or assumption of naturalism in scientific belief and practice.*

Of course science can meaningfully exist exactly because there are natural laws that are consistent. Nobody questions the usefulness of science for understanding the natural world. But does science require any philosophy to "imply a unity and lawfulness in nature" and does a scientist necessarily need a philosophy to practice science? According to evolutionists it does...

Naturalism is a methodological necessity in the practice of science by scientists, and an ontological necessity for the understanding and credibility of science ... A methodological naturalist is using naturalism as a philosophy... Science adopts methodological naturalism ... If an individual is attempting to explain some aspect of the natural world using science, he or she must act as if there were no supernatural forces operating on it... science cannot consider the supernatural, so a scientist must adopt, at least, methodological naturalism.*

According to evolutionists who are in control of mainstream science scientists must adopt methodological naturalism which means that they must "adopt naturalism". But in reality science is independent of any philosophy, and independent of which philosophy or belief is held by the scientist. It seems that this evolutionist contradicts himself...

Science investigates the natural, the supernatural may exist as part of ultimate reality, so let's not say that the natural is all that exists because that is what science investigates.*

The reality is that both science and naturalism are limited. Science can study the natural world, but neither science nor naturalism can explain where the natural world comes from in the first place. This is a philosophical question. The evolutionist admits that "the supernatural may exist as part of ultimate reality".

Galileo and Newton were not naturalists; they did not hesitate to attribute supernatural causes to things that they thought could not be explained by natural causes. Until the late eighteenth century, most scientists agreed with them, but the influence of the Enlightenment led scientists, such as Antoine Laurent Lavoisier, Pierre Simon de Laplace, and James Hutton to abandon all supernatural explanations in favor of natural ones. Biology was the last science to be so treated, by Jean Baptiste Lamarck and Charles Darwin.*

Naturalists took control of the world of mainstream science. But that doesn't mean that for example some of the greatest scientists of all time like Galileo or Newton were not right about their philosophical conclusions. Based on their scientific discoveries they concluded philosophically and logically that the natural world, precisely because of its natural laws, was best explained as caused by intelligence, not by mindless naturalistic laws and processes. Their beliefs or philosophy didn't obstruct their science proving that science is independent of philosophy.

The naturalists of the 19th century believed in steady-state theory, that everything was without beginning, and that they didn't need to explain the first causes of the universe and nature. But their belief was disproved by the big bang theory in the 20th century and the growing evidence for the fine-tuning of the universe. The question of the coming into existence of everything became more relevant. Naturalists believed biological cells to be simple protoplasms, but the true science of genetics in the 20th century revealed the incredible specified complexity of cells and the DNA contained in them. Thus naturalism had to explain the coming into existence of specified information.

With the advancement of true science more and more complexity of the universe and life was revealed and the problems for naturalism became dilemmas. What true scientists and geniuses like Galileo and Newton already realized in the 17th century was that the best explanation for the scientific knowledge available at that time was more than enough reason to believe that intelligence was involved. Whether they called it God or not doesn't matter to their science. Specified complexity is caused by intelligence, not by mindless naturalistic processes as the naturalists in the 20th century and beyond would like to believe.

Science neither denies nor opposes the supernatural, but ignores the supernatural for methodological reasons.*

Science itself doesn't deny or oppose any philosophy, but naturalists in control of mainstream science since the 19th century deny and oppose supernaturalism for philosophical reasons. The philosophies and beliefs of Galileo and Newton had no effect on their science and they are rightly regarded as two of the greatest scientists who ever lived. The naturalists since the 19th century, on the other hand, imposed their philosophy and belief on science and it clearly had a great influence. But ideally science is free of any philosophy, whether that be supernaturalism or naturalism.

Rudolf Otto:
Naturalism is not of to-day or of yesterday, but is very ancient... Even in its most highly developed form we can see that it did not spring originally from a completed and unified principle, but was primarily criticism of and opposition to other views. ... Naturalism has always arisen in opposition to what we may call "supernatural" propositions.

According to evolutionist Franklin M. Harold...
We should reject, as a matter of principle, the substitution of intelligent design for the dialogue of chance and necessity; but we must concede that there are presently no detailed Darwinian accounts of the evolution of any biochemical system, only a variety of wishful speculations.

Naturalism is opposed to supernaturalism. Just like materialism is opposed to spirituality. It is closely related to atheism, the opposition to theism or belief in God. Honest atheists admit that Darwinian evolution does not and cannot explain life, but they believe it nonetheless because they have nothing else and are fundamentally opposed to all other worldviews because those other worldviews lead to for example supernaturalism and God.

Here is the mind of typical atheist Thomas Nagel:
I want atheism to be true and am made uneasy by the fact that some of the most intelligent and well-informed people I know are religious believers. It isn't just that I don't believe in God and, naturally, hope that I'm right in my belief. It's that I hope there is no God! I don't want there to be a God; I don't want the universe to be like that.

Atheism requires a closed and narrow mind. And that's unscientific to begin with. Atheist Mikhail Bakunin famously said that If God really existed, it would be necessary to abolish him. C. S. Lewis captured it well when he said that Atheists express their rage against God although in their view He does not exist.

Since no human method can possibly prove or disprove the supernatural, atheism has to be taken by faith. Atheism is the belief that there exists no God. The atheist doesn't want God. This idea has fundamentally affected his search for a reason to expell God from the world and the human mind.

Karl Popper:
I don't know whether God exists or not. ... Some forms of atheism are arrogant and ignorant and should be rejected, but agnosticism—to admit that we don't know and to search—is all right.

The philosophy atheism goes hand in hand with the philosophy naturalism. Evolutionists, most of whom are also atheist, are in control of mainstream science and their philosophy has a profound impact on their science.

Gustave Le Bon:
Were it possible to induce the masses to adopt atheism, this belief would exhibit all the intolerant ardour of a religious sentiment, and in its exterior forms would soon become a cult.

The so-called New Atheists are aggressively opposed to anything that is related to God or the supernatural. They are self-styled fighters of religion but they fanatically preach the religion of evolution. They claim to oppose faith, but they put all their faith in atheism. They claim to be the defenders of truth, just like the religious people they claim to be fighting. They are trapped in a corrupt mindset because in many fundamental ways they fanatically practice the very thing they claim to oppose. Miles Mathis nicely said that atheism is a belief just as firmly planted in irrationality, in ego and desire, as theism. Atheism has no proof and no possible proof. It is unscientific.* But these are the kind of people with much influence in, and hailed by, mainstream science. Birds of a feather flock together.