Naturalism is a worldview which holds that the cosmos and life came into existence and operate through natural processes alone. The explicit and sole focus on the natural world has driven modern science into accepting naturalism as the predominant philosophy of science. Naturalism does not appeal to the supernatural or nonphysical reality for explanations at any time and because of that many Christian philosophers like Alvin Plantinga, William Lane Craig and Peter van Inwagon have deemed naturalism as maintaining a stronger stance than atheism. According to Plantinga naturalism not only presupposes the non-existence of God but extends over all areas of life answering a range of deep existential questions like how life should be viewed, what the world is fundamentally made of and what the purpose of humanity actually is. From this metaphysical position philosophers have charged naturalism as being a worldview and thus granting the cognitive functions of a religion missing support for only the outward actions of worship and/or ritual.
Metaphysical naturalism (also called ontological naturalism, philosophical naturalism and scientific materialism) is a worldview in which reality is composed of nothing but natural things, forces, and causes. All concepts related to consciousness or to the mind refer to entities which are reducible to the same such natural things, forces and causes. Within naturalism's metaphysics there is no objective existence of any supernatural being, force or cause, such as are described in various religions and mythological accounts. All supernatural things are ultimately explainable purely in terms of natural things. Metaphysical naturalism is a monistic and not a dualistic view of reality.
The explicit and sole focus on the natural world has driven modern science into accepting naturalism as the predominant philosophy of science. Many Christian philosophers like Alivn Plantinga and William Lane Craig have deemed naturalism as maintaining a stronger stance than atheism. According to Plantinga naturalism not only presupposes the non-existence of God but extends over all areas of life answering a range of deep existential questions like how life should be viewed, what the world is fundamentally made of and what the purpose of humanity actually is. From this metaphysical position philosophers have charged naturalism as being a worldview and thus granting the cognitive functions of a religion missing support for only the outward actions of worship and/or ritual.
|“||Due to the typical attitude of the contemporary naturalist, which is similar to the attitude expressed by Searle in the previous quote, the vast majority of naturalist philosophers have come to hold (since the late 1960s) an unjustified belief in naturalism. Their justifications have been defeated by arguments developed by theistic philosophers, and now naturalist philosophers, for the most part, live in darkness about the justification for naturalism. They may have a true belief in naturalism, but they have no knowledge that naturalism is true since they do not have an undefeated justification for their belief. If naturalism is true, then their belief in naturalism is accidentally true.||”|
Naturalism is an ancient doctrine, and has existed in constant conflict with theism and supernaturalism, as exhibited by ancient manifestos of naturalism such as On the Nature of Things. It is now the dominant doctrine of modern science. The word naturalist today usually refers to one who holds this philosophy, although in the 19th century the term "naturalist" was used to refer to one who studied nature.
Founders of modern science, such as Galileo Galilei and Isaac Newton, viewed natural events with a different philosophy than those who promote many standard models since Darwin. Most of the pioneers of science believed in a God who created a universe of order, a universe that now operates under natural laws or processes. They believed that God created the world without the restrictions of the laws that we, as imperfect humans, understand. In other words, God created supernaturally, but the resulting universe now operates predictably: naturally.
Naturalism refers to a belief about the totality of what exists. It is a belief that nature is all that exists and assumes that observable events in nature are explained only by natural causes, and that supernatural causes are not possible. The only way that anyone can know if indeed the cosmos is all there is as Sagan and many evolutionists assume when interpreting date, is if they know everything there is to know about the Cosmos. This of course is a position that is impossible for a human to be in and therefore is an assumption based upon incomplete knowledge. Any lack of knowledge allows for the possibility of something else besides the Cosmos. The scientific methodology of investigation to acquire knowledge cannot be the source of the position, so it resides in the realm of philosophy. If everything were known that could be known there would be no need for science. There could perhaps be one way to know everything is if full knowledge of the Cosmos existed for as long as the Cosmos, but of course human knowledge has not existed as long as the cosmos. Any lack of knowledge about the past allows for the possibility that it has not ever been. Not only must one know everything about the cosmos and its past, the person must also know everything about its future. Science deals with the repeatable present based on observation within the natural world, so is no help in knowing the future. There is no one apart from a necessary, transcendent timeless being like God who can possibly assert the truth in such a matter. Creationists believe in what God has said on the matter through a position of revealed theology. This is not blind faith, it is faith that comes from spiritual and religious experience as well as philosophical argumentation that support evidences of God and thus a reasonable faith.
|“||The Cosmos is all there is, has ever been or ever will be||”|
- Main Article: Worldview
The Scripture does not use the terms "natural" or "supernatural", nor does it use these concepts in particular. The Bible uses the terms "heavenly", "spiritual", "earthy/earthly", "temporal", "seen" and "unseen", etc. The terms "natural" and "supernatural" are in fact secular definitions used to delineate between the physical, measurable existence (natural) and make-believe (supernatural). In other words, for the secularist, the term "supernatural" is where all make-believe has a home, whether God, demons, angels and eternal souls, but also zombies, vampires, pixies, faeries etc. Conversely, the "natural" world is the world where "God is not". The Scripture asserts (Hebrews 1:3) that the entire creation is upheld by the "word of his power". So there is no place in the creation where "God is not". This means that the "natural world" that the secularist believes in, doesn't exist. It's make-believe. And if this is true, then the supernatural world that the secularist designates as make-believe, is completely make-believe. In short, the claims of the secularists of a natural/supernatural world are contrived. There's no such thing as either one. There is only "the creation", made with living creatures and heavenly beings which cohabitate on the same space/matter/time fabric.
Naturalists reject miracles on philosophical grounds, since God and spiritual explanations are outside of the naturalistic framework. Some naturalists seek to define words like science in such a way rejecting creationism out-of-hand as non-science. In the context of the creative events of Genesis, the supernatural can be defined as laws and principles (of the operations of matter) that are natural to God, but not to humans. For example, God uses laws and principles known to Him to affect miracles like the parting of the Red Sea, but also used natural forces (a great wind) to assist in its execution. God claims that his laws are immutable, so does not suspend nor set-aside his laws to affect a miracle. Just as we use the laws of aerodynamics to overcome the effects of the laws of gravity (to enable flight), so God has laws unknown to humans that enable him to operate the universe as he requires. For example, to someone isolated from modern technology, the operation of an airplane is supernatural and miraculous; to an airplane mechanic, the parts of the airplane operate according to natural laws that are known and understood. Naturalism rejects realities that cannot be measured or detected by the human senses. Consequently naturalism would reject angels, demons, and spirits such as God himself who is a Spirit and has not a body like ours. Paradoxically, many naturalists will accept elements of astrology.
Metaphysical naturalism represents a particular view about ultimate existence and hence belongs to the philosophical field of ontology. In practice the use of the term metaphysical naturalism reduces to the more specific ontological view of scientific naturalism because modern science demands naturalistic explanations. It forms the philosophical foundation of methodological naturalism which represents a particular view of how one may arrive at knowledge about reality and which hence belongs to the philosophical field of epistemology. Metaphysical naturalists ought to begin by examining their epistemology. Constructing an epistemology based on metaphysical naturalism in a reasonable and thoughtful way requires an examination of what is being investigated, seeking how to discover if it is a possibility, and spending the time necessary to reach conclusions. In practice, however, one's epistemology is but superficially examined and applied merely by intuition. More often, it is simply borrowed from parents, teachers, or peers and not critically examined or constructed by the individual. If one has not even thought about it, much less carefully examined and tested what one thinks one knows, it's unlikely that one's unexamined assumptions will just by pure chance be sound and trustworthy. Everything done, believed and desired ultimately depends upon one's knowledge being correct.
Physicalism and pluralism
There are two general categories of metaphysical naturalism: physicalism and pluralism. Physicalism entails the claim that everything everyone has observed or claimed to observe is actually the product of fundamentally random arrangements or interactions of matter-energy, arrangements or interactions that follow natural laws of physics, in space-time, and therefore it is unreasonable to believe anything like a creator deity exists. Pluralism (which includes dualism) adds to this the existence of fundamentally random things besides matter-energy in space-time. Other forms of metaphysical naturalism agree with the science of scientific naturalism, but its metaphysical conclusions differ over abstract objects like "mind," "soul," "free will," or anything having to do with self-made men.
Methodological naturalism is the label for the required assumption of philosophical naturalism when working with the scientific method. The terms philosophical naturalism and ontological naturalism all refer to or ultimately underpin methodological naturalism. Methodological naturalism entails the assumption that observable events in nature are explained only by natural causes, extrapolating up to include the entire universe. Empirical methods will only ascertain facts, yet reliance on extrapolation pushes this thinking into a philosophy.
|“||Since philosophy is at least implicitly at the core of every decision we make or position we take, it is obvious that correct philosophy is a necessity for scientific inquiry to take place.||”|
There are basic philosophical assumptions implicit at the base of the scientific method - namely, that reality is objective and consistent, that humans have the capacity to perceive reality accurately, and that rational explanations exist for elements of the real world. Supernatural explanations is not explicitly denied, they would say but rather ruled out as a possibility, those types of explanations are considered outside of the methodological naturalism realm. In other words the distinction between the two is largely word games because strict philosophies always gird science so that they always share that in common. These assumptions are the basis of naturalism, the philosophy on which science is grounded.
Besides the basic beliefs already described above, most if not all contemporary naturalists believe the following as the logical consequences of the core beliefs of naturalism. These form the basis for naturalistic interpretation of science.
The universe has either always existed or had a purely natural origin, being neither created nor designed. Either way, naturalists hold nature (rather than, say, God or Tao) to be the ground of all being. The popular Big Bang cosmology was developed within this assumption, proposing that the observable universe had a beginning, unfolding from a process of natural laws. But this does not resolve the question of whether all that exists began to exist at once or whether a being of some sort has always existed. Some naturalists propose a multiverse theory where it is thought that the observable universe is only part of a much larger whole. Citing the first law of thermodynamics, other naturalists propose that matter has always existed; matter, not the universe in its current state, exists eternally. 
The concept of time as associated with the existence of a universe or universes is known as Deep Time. Its measurement is conceived in billions of earth years. As an indispensable part of the Cosmos, deep time is an accepted fact, not an hypothesis. "By recognizing the vastness of Earth history compared to human history, we internalize what John McPhee has termed Deep Time"
- Main Article: Abiogenesis
Since matter is all there is, and since there are no gods to interact with the universe, abiogenesis (life arising from inorganic matter according to natural law) is an unqualified certainty, not a hypothesis. There are several current hypotheses about how abiogenesis happened, but thus far a conclusive explanation of how abiogenesis works remains elusive. The concepts of Panspermia and Exogenesis move the problem of the origin of life to elsewhere in the universe solving nothing.
- Main Article: Evolution
Since there were once only simple lifeforms and now there is a rich diversity of life on Earth (the existence of creative gods is precluded) evolution by natural selection or other means is a verity of the naturalist worldview. While scientific hypotheses of how the evolutionary process took place over deep time are widely discussed, belief in the fact of evolution is unshakable.
Mind as brain
- Main Article: Mind
Human beings have no independent soul or spirit, but only a material brain, which operates to produce a conscious mind. Since one's mind, and hence one's identity and existence as a person, is entirely the product of a physical process, three conclusions follow. First, all mental contents (such as ideas, theories, emotions, moral and personal values, or beauty and ugliness) exist solely as computational constructions of the brain, and not as things that exist independently of conscious thought. Second, damage to the brain (from disease, drugs, malnutrition, or injury) frequently entails damage to the self and therefore should be of great concern. Third, the death or destruction of one's brain cannot be survived, and therefore all humans are mortal. Given present technology, this means that death is inevitable and causes the complete extinguishment of an individual. Since this entails there is no afterlife, naturalists argue humans need to accept this and make the most of what they have. 
- The Nature of Nature: Examining the Role of Naturalism in Science, "Evolution versus Naturalism" by Alvin C. Plantinga. Pg 137.
- The Religion of Evolution by Gary DeMar, September 30, 2002
- Bruce L. Gordon and William A. Dembski, The Nature of Nature: Examining the Role of Naturalism in Science (Intercollegiate Studies Institute 2011), pg. 137
- Stanford Encyclopedia of Philosophy: religion-science
- The Metaphilosophy of Naturalism By Quentin Smith, Philo Volume 4, Number 2
- Carl Sagan, Cosmos, pg. 1
- Carrier, Richard, 2005, Sense and Goodness without God: A defense of Metaphysical Naturalism, AuthorHouse, p23-24
- A., Kate, & Sergei, Vitaly, 2000, Evolution and Philosophy: Science and Philosophy, access date 21 September 2009
- Palmer, A. R. & E-an Zen, The Context of Humanity: Understanding Deep Time Access date: 21 September 2009
- Varieties of Naturalism By John Shook
- "Moral Naturalism" in the Stanford Encyclopedia of Philosophy
- "Naturalism" in the Internet Encyclopedia of Philosophy
- "Naturalism" in the Stanford Encyclopedia of Philosophy
- "Naturalism in Legal Philosophy" in the Stanford Encyclopedia of Philosophy
- "Naturalism in the Philosophy of Mathematics" in the Stanford Encyclopedia of Philosophy
- "Physicalism" in the Stanford Encyclopedia of Philosophy
- Naturalism All About Philosophy
- Naturalism Philosophical and Methodological by Genesis Science Mission
- Naturalism in science by Genesis Mission
- Origin of life
- Science is naturalistic Response to Talk.Origins
- Naturalistic science will miss a supernatural explanation Response to Talk.Origins