Natural theology is a realm of Christian theology that expounds on beliefs about the nature of God by excluding divine revelation in holy scriptures as authoritative for theology. Appeal to the authoritative truth from the Bible is called revealed Christian theology and it forms theological doctrines about the nature of God on completely different sets of criteria. This is achieved by exegesis of verses found in the Old Testament and New Testament and deep investigations into the background of the authors. Alternatively natural theology bases itself within the realm of science and philosophy. The natural world is given epistemological authority as a way to know the nature of God. The assumption is that the human mind is rational and able to know and understand nature because the origin of it is found in a rational creator. Philosophical argumentation and scientific evidences are the means by which natural theology is articulated and systematized. Not to falsify specific theories as such but to probe the nature of nature. To show logically that inference to transcendent cause over matter is the metaphysically necessary being God.
Natural theology begins with the natural world and reasons from that evidence rather than from a divine text. There is interplay within Christian theology of both natural theology and revealed theology as they find themselves intersecting by employing the enterprise of philosophy at the same time. Constituting an epistemology about the nature of God.
|“||What the natural theologian sets out to do is to show that some of the central beliefs of theism follow deductively or inductively from propositions that are obviously true and accepted by nearly every sane man (e.g., Some things are in motion) together with propositions that are self-evident or necessarily true. In this way he tries to show that certain pivotal religious beliefs—particularly the existence of God and the immortality of the soul—are rationally justifiable.||”|
Plato (427–347 BC) in Book VII of The Republic expounds upon an imaginative story that intends to capture how the mind, the intellect or the soul is illuminated by revelations found in nature. Plato depicts human beings since childhood shackled in a dark cave, even their legs and necks chained disabling them the ability to merely turn their heads. Above and behind them a fire "blazing at a distance", and yet there is still more to this allegory because in-between the fire and the shackled prisoners are marionette players carrying all sorts of figurines, vessels and objects made up of different materials. These cast strange and mysterious shadows to the shackled prisoners. These prisoners are confined strictly to see only that which the fire casts a shadow upon, their knowledge of the world is limited like the darkness of shadows seen and thought to be the only thing existing by limited experience. The imagery by Plato is then articulated by supposing an echo came from the other side of the cave, and inferring that the prisoners would posit the voice had come from the shadows.
|“||And suppose further that the prison had an echo which came from the other side, would they not be sure to fancy when one of the passers-by spoke that the voice which they heard came from the passing shadow?||”|
The allegory of the cave by Plato climaxes when the prisoners are released and emerge into the world outside. The prisoners are led and guided by an instructor who attempts to educate them as their sight adjusts to reality they never knew. They are guided by the instructor and they can only gaze for moments at the surroundings and outlines of objects by way of the shadows. Not able to fully comprehend the breathtaking beauty of the world outside by sight. The sun is far to bright to even glimpse at yet. The prisoners adjust more and more and are reluctantly led up to where they may fixate toward the heavens and ultimately at the sun. The light source from which gives all life it would seem. The sun illuminates the reality of the world for the once prisoners, and that is the Form of the Good. It is a new stage of understanding initiated through education in light of the Good. It leads from mere sensory exploration of humans into knowledge of the form of the Good. The form of the Good essentially can be seen as the cause of why there is something (being and thus knowledge) rather than nothing (non-being) called the first principle by Plato.
Plato seems to be articulating a way to argue from nature for God or what he calls The Good. Michael Ayers writing in the Cambridge University Companion to Berkeley characterizes the allegory in this way;
|“||If we cannot gaze directly at the divine sun in this life, we can at least momentarily perceive it to be the origin of the natural light by which we apprehend truth, a piece of knowledge which, once achieved, permanently validates that light.||”|
|“|| And now look again, and see what will naturally follow it' the prisoners are released and disabused of their error. At first, when any of them is liberated and compelled suddenly to stand up and turn his neck round and walk and look towards the light, he will suffer sharp pains; the glare will distress him, and he will be unable to see the realities of which in his former state he had seen the shadows; and then conceive some one saying to him, that what he saw before was an illusion, but that now, when he is approaching nearer to being and his eye is turned towards more real existence, he has a clearer vision, -what will be his reply? And you may further imagine that his instructor is pointing to the objects as they pass and requiring him to name them, -will he not be perplexed? Will he not fancy that the shadows which he formerly saw are truer than the objects which are now shown to him?
Clearly, he said, he would first see the sun and then reason about him. 
Plato however envisions an impersonal representation of the Good. The language attempts to personify the sun but Plato did not ground concepts like justice or morality into that nature of the Good. They remain as abstract objects and intrinsically relative within his works. William Lane Craig, a Christian philosopher, takes direct issue with this essential of Platonism considering it a deficiency.
|“||What is deficient in Plato’s theory is a person who can issue moral imperatives as an expression of the Good; but that want is supplied by theism. So it seems to me that Divine Command Theory’s derivation of an “ought” from an “is,” far from being objectionable, captures a central feature of moral duty and plausibly grounds it.||”|
Aristotle (384–322 BC) in Physics through observation of natural motions concluded a first mover of things, a force unmovable who set things into motion. In a later writing called Metaphysics Aristotle identifies the unmoved mover as separate from matter and its nature that of a disembodied mind.
Plato and Aristotle were two ancient philosophers that uncovered two distinct ways to investigate reality and truth. There was firstly "poetic-mythological-theological" or what can be called revealed theology in modern terms, and secondly the rational human mind that starts and ends with observation in nature (natural theology).
New Testament Natural theology
Paul is widely considered to teach Christian natural theology in Romans 1. All that is done by contemporary thinkers of natural theology is that they articulate the reasons how Gods invisible attributes are known by philosophical argumentation.
20 For since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through what has been made, so that they are without excuse. Romans 1:20 (NASB)
During medieval philosophy arguments for God without relying on revelation underwent considerable exploration producing many different paths spurring many timeless debates still central to natural theology today. Anselm of Canterbury in the 11th century and Thomas Aquinas in the 13th century made great strides with natural theology inside of the western philosophical tradition. The first published philosophical writings in English were that of natural theology called The True Intellectual System of the Universe by Ralph Cudworth (1617–88).
According to The Blackwell Companion to Natural Theology in the essay entitled "The Project of Natural Theology" by Charles Taliaferro natural theology played an important role in the development of modern philosophy;
|“||Natural theology played a major role in early modern philosophy. Some of the classics in the modern era, such as the Meditations by Descartes (1596–1650), An Essay Concerning Human Understanding by John Locke (1632–1704), Three Dialogues between Hylas and Philonous by George Berkeley, the Theodicy by Leibniz (1646–1716), the Dialogues Concerning Natural Religion by David Hume (1711–76), and the Critique of Pure Reason by Immanuel Kant(1724–1804) all constitute major contributions to assessing reasons for and against theism, without making any appeal to revelation.||”|
- Main Article: Cosmological argument
The cosmological argument is not a single argument but actually an entire family of philosophical arguments (logos; See: Logic) found in natural theology. There are subtle differences between versions of the cosmological argument and seek to demonstrate, by way of a priori and empirical (a posteriori) arguments, a "Sufficient Reason or First Cause" for the cosmos. The family of cosmological arguments hold together through a common metaphysics. Theism throughout the history of the argument has been necessary so that any version requires a transcendent First Cause. Or, to put another way, a space-less, timeless, beginning-less, eternal, supernatural being of unimaginable power, namely God, is the cause of the origin of the universe. It is from this position then that a short traverse can be made into apologetics for the resurrection of Christ as how God has revealed Himself to humanity. (See: Minimal facts method)
|“||It uses a general pattern of argumentation (logos) that makes an inference from certain alleged facts about the world (cosmos) to the existence of a unique being, generally identified with or referred to as God. Among these initial facts are that the world came into being, that the world is contingent in that it could have been other than it is, or that certain beings or events in the world are causally dependent or contingent.||”|
- Main Article: Teleology
Teleology is the position that there is design, purpose, directive principle, or finality in the works and processes of nature, and the philosophical study of that purpose.
Teleology stands in contrast to philosophical naturalism, and both ask questions separate from the questions of science. While science investigates natural laws and phenomena, philosophical naturalism and teleology address and investigate the existence or non-existence of an organizing principle behind those natural laws and phenonema. Philosophical naturalism asserts that there are no such principles. Teleology asserts that there are.
For example, the view of philosophical naturalism is that man sees because he has eyes. Teleology, on the other hand, holds both that man sees because he has eyes and has eyes so that he can see. As Aristotle wrote in support of teleology, "Nature adapts the organ to the function, and not the function to the organ" (De partib., animal., IV, xii, 694b; 13). Lucretius replied in support of philosophical naturalism: "Nothing in the body is made in order that we may use it. What happens to exist is the cause of its use." (De nat. rerum, IV, 833; cf. 822-56)
- Main Article: Intelligent Design
Intelligent Design (ID) refers to a theory of origins or a scientific research program. In addition, the term is used to describe the community of philosophers, scholars, and scientists who are seeking evidence of design in nature. The scientific theory of intelligent design holds that;
|“||certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection. ||”|
ID theorists draw exclusively upon empirical evidence to support the existence of a creative intelligence or designer. ID purports that design can be detected without any understanding of who the designer is or why the agent acted, or even how the phenomenon in question was actually produced. ID is a unique scientific position that stands in stark contrast to naturalistic, materialistic philosophy of science which puts forth abiogenesis rather then intelligent agents as the main mechanism that created biological systems for sustaining life. It can also clearly be distinguished from religious creationism in that it stakes no claim regarding the specific identity of the creator, nor does it use references from scripture when forming theories about the history of the world. In fact, many ID theorists support the idea of common descent and billions of years of time. ID simply postulates that certain features within the cosmos present clear evidence of being deliberately and intelligently designed.
Views on God
The predominant forms of natural theology in philosophy today are theistic and deistic.
- Main Article: Theism
Theism is the religious metaphysical philosophy that asserts God exists and that He created and sustains the cosmos. Classical theism supports a creator God that not only exists but is omniscient, omnipresent, exists necessarily, is nonphysical, eternal and essentially good. The Cambridge Companion to Atheism puts the philosophical position of theism as, "coming to mean a belief in a personal God who takes an active interest in the world and who has given special revelation to humans." The most competitive alternative philosophy within the modern intellectual climate is metaphysical naturalism. An entrenched philosophy of science acting without the existence of God and the soul, preceding with the assumption of strict materialism.
- Main Article: Deism
Deism is the theological position that God created the world, but then left it to run without any divine intervention. It rejects all miracles and divine revelation and asserts that religion should be derived by reason alone. This was a common position of Enlightenment thinkers, although naturally it has no support from the Bible.
- William Lane Craig and J. P. Moreland, The Blackwell Companion to Natural Theology (Blackwell Publishing 2009), pg. 1
- Has Science buried God? The quote is: "I believe the Universe is rationally intelligible precisely because there is a Creator-God behind it. How do you account for the rational intelligibility of the Universe? "
- The Epistemology of Religion By Stanford Encyclopedia of Philosophy. First published Wed Apr 23, 1997; substantive revision Wed Mar 11, 2009
- Alvin Plantinga, God and Other Minds: A Study of the Rational Justification of Belief in God (Cornell University Press 1990), pg. 4
- Plato, The Republic, Book VII
- Kenneth P. Winkler, The Cambridge Companion to Berkeley (Cambridge University Press 2005), pg. 39
- Question 165, Subject: Does Theistic Ethics Derive an "Ought" from an "Is"? Response by William Lane Craig
- Natural Theology. 1. Historical Beginnings of Theology and Philosophy Internet Encyclopedia of Philosophy
- William Lane Craig and J. P. Moreland, The Blackwell Companion to Natural Theology (Blackwell Publishing 2009), pg. 1-2
- J. P. Moreland and William Lane Craig, Philosophical Foundations for a Christian Worldview (IVP Academic 2003), pg 465
- Cosmological argument by Bruce Reichenbach. Stanford Encyclopedia of Philosophy, 2008
- The Theory of Intelligent Design: A Briefing Packet for Educators p6. by Discovery Institute. November, 2007.
- Michael Martin, The Cambridge Companion to Atheism (Cambridge University Press 2007), pg. 1-2
- William Lane Craig and J. P. Moreland, The Blackwell Companion to Natural Theology (Blackwell Publishing 2009), pg. 8
- Natural Theology By Dr. Douglas Groothuis Apologetics MP3
- Revealed Theology, Natural Theology, and the Darwinist Concoction of “ID/Creationism.” By StephenB for Uncommon Descent blog
- Question 66, Subject: Christianity Today Article and God's Personhood Response by William Lane Craig
- The Principles of Moral and Political Philosophy By William Paley. 1785.
- Natural Theology By Wikipedia
- Evidence of Christianity By William Paley. 1851.
- Natural theology: or, Evidences of the existence and attributes of the Deity, Collected from the Appearances in Nature By William Paley, James Paxton. 1817