Teleological Argument for the Existence of God

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The "Teleological Argument for the existence of God" is a member of the classic triad of arguments, which is completed by the Ontological Argument and the Cosmological Argument. Stated most succinctly, it runs:

The world exhibits teleological order (design, adaptation).

Therefore, it was produced by an intelligent designer.

To understand this argument, we must first understand what teleological order is.

Teleological Order

Generally speaking, to say that a group of elements is ordered in a certain way is to say that they are interrelated so as to form a definite pattern, but the notion of a definite pattern is vague. Any set of elements is interrelated in one way rather than another, and any complex of interrelations might be construed by someone as a definite pattern. Certain patterns are of special interest for one reason or another, and when one of these is exhibited, the complex would ordinarily be said to be ordered. Thus, when the elements form a pattern in whose perception we take intrinsic delight, we can speak of aesthetic order. When there are discernible regularities in the way, certain elements occur in spatiotemporal proximity, we can speak of causal order. The distinctive thing about teleological (Greek, telos, "end" or "goal") order is that it introduces the notion of processes and structures being fitted to bring about a certain result.

The usual illustrations of teleological order are from living organisms. It is a common observation that the anatomical structures and instinctive activities of animals are often nicely suited to the fulfillment of their needs. For example, the ears of pursuing, carnivorous animals, like the dog and the wolf, face forward so as to focus sounds from their quarry, while the ears of pursued, herbivorous animals, like the rabbit and the deer, face backward so as to focus sounds from their pursuers.

Examples of instinctive behavior are even more striking. The burying beetle deposits its eggs on the carcass of a small animal and then covers the whole "melange" with dirt to protect it until the young hatch out and find an ample supply of (hardly fresh) meat at hand.

If we are going to distinguish teleological order from causal order, we shall have to make explicit the tacit assumption that the result the structure or process in question is fitted to bring about is of value. Otherwise, any cause-effect relationship would be a case of teleological order. It is just as true to say that wind is fitted to produce the result of moving loose dirt into the air as it is to say that the mechanism of the eye is fitted to produce sight. The latter would be counted as an example of "design," whereas the former would not, because we regard sight as something worth having, whereas the movement of dirt through the air is not generally of any value. This has the important implication that insofar as it is impossible to give an objective criterion of value, it will not be an objective matter of fact that teleological order is or is not exhibited in a given state of affairs.

It is important to note that the term design, as used in this argument, does not by definition imply a designer. If it did, there could be no argument from design to the existence of God; we would have to know that the phenomena in question were the work of a designer before we could call them cases of design. We must define design in such a way as to leave open the question of its source. We have design in the required sense when things are so ordered that they tend to perform a valuable function. We might put this by saying that things are ordered as they would be if some conscious being had designed them, but in saying this we are not committing ourselves to the proposition that a mind has designed them. The equivalent terms adaptation and teleological order are not so liable to mislead in this way.

Arguments for the existence of God have been based on kinds of order other than the teleological. Exhortations to move from a consideration of the starry heavens to belief in God constitute an appeal to aesthetic order. It is sometimes claimed that we must postulate an intelligent creator to explain the regularity with which the solar system operates. Here it is causal order that is involved. Arguments like these are often not clearly distinguished from those based on teleological order, to which we shall confine our attention.

Arguments from Particular Cases of Design

The simplest form of the argument is that in which we begin with particular cases of design and argue that they can be adequately explained only by supposing that they were produced by an intelligent being. Thus William Paley, an eighteenth-century philosopher, in a classic formulation of the argument concentrated on the human eye as a case of design, stressing the ways in which various parts of the eye cooperate in a complex way to produce sight. He argued that we can explain this adaptation of means to end only if we postulate a supernatural designer. This is the heart of the teleological argumentthe claim that adaptation can be explained only in terms of a designer. It always rests, more or less explicitly, on an analogy with human artifacts. Thus, Paley compared the eye to a watch and argued as follows: If one were to find a watch on a desert island, one would be justified in supposing that it was produced by an intelligent being. By the same token (the adjustment of means to ends) one is entitled, upon examination of the human eye, to conclude that it was produced by an intelligent being.

If it is asked why we should take artifacts as our model, the answer would seem to be this. Artifacts are certainly cases of design. In a watch, for example, the structure is well suited to the performance of a valuable function: showing the time. With artifacts, unlike natural examples of design, we have some insight into what is responsible for the adjustment of means to end. We can understand it because we can see how this adjustment springs from the creative activity of the maker, guided by his deliberate intention to make the object capable of performing this function. Hence, in natural cases of adaptation where the source of the adaptiveness is not obvious, we have no recourse but to employ the only way we know of rendering such phenomena intelligiblesupposing them to stem from conscious planning. Since we do not observe any planner at work, we must postulate an invisible planner behind the scenes.


The comparison to artifacts was attacked by David Hume in his Dialogues concerning Natural Religion, in which he suggested that the production of artifacts by human planning is no more inherently intelligible than the production of organisms by biological generation. Why, asked Hume, should we take the former rather than the latter as the model for the creation of the world? Even if we admit that the world exhibits design, why are we not as justified in supposing that the world was generated from the sexual union of two parent worlds as in supposing that it was created by a mind in accordance with a plan? In answer to Hume it might be argued that creation gives a more satisfactory and a more complete explanation than generation because the generation consists of a reproduction of the same kind of thing and hence introduces another entity that raises exactly the same kind of question. If we are initially puzzled as to why a rabbit has organs that are so well adapted to the satisfaction of its needs, it does not help to be told that it is because the rabbit sprang from other rabbits with just the same adaptive features. If, on the other hand, we could see that the rabbit had been deliberately constructed in this way so that its needs would be satisfied, we would be making progress. To this Hume would reply that the mind of the designer also requires explanation. Why should the designer have a mind that is so well fitted for designing? Thus, this explanation also leaves problems dangling, but at least it is not just the same problem. If we were to reject every explanation that raised fresh problems, we would have to reject all of science.

darwinian theory of evolution

The development of the Darwinian theory of evolution opened up the possibility of a more serious alternative to the theistic explanation. According to this theory, the organic structures of today developed from much simpler organisms by purely natural processes. In this theory (as developed since Charles Darwin) two factors are considered to play the major role: mutations and overpopulation. (A mutation occurs when an offspring differs from its parents in such a way that it will pass this difference along to its offspring, and they will pass it along, and so on. It is a relatively permanent genetic change.)

The way these factors are thought to work can be illustrated by taking one of the cases of adaptation cited above. If we go back far enough in the ancestry of the dog, we will discover ancestors that did not have ears facing forward. Now let us suppose that a mutation occurred that consisted of an ear turned somewhat more forward than had been normal. Granting that organisms tend to reproduce in greater numbers than the environment can support, and hence that there is considerable competition for the available food supply, it follows that any feature of a given organism that gives it any advantage over its fellows in getting food or in avoiding becoming prey will make it more likely to survive and pass along its peculiarity to its offspring. Thus, within a number of generations we can expect the front-turned-ear proto-dogs to replace the others and be left in sole possession of the field. Since mutations do occur from time to time, and since some of them are favorable, we have a set of purely natural factors by whose operation the organic world can be continuously transformed in the direction of greater and greater adaptation.

The Darwinian theory aspires to do no more than explain how more complex organisms develop from less complex organisms. It has nothing to say about the origins of the simplest organisms. However, no matter how simple the organism, its structure must be fitted to the satisfaction of its needs, or it will not survive. Therefore, Darwinian theory is not a complete explanation of the existence of teleological order in the world; it merely tells us how some cases develop from other cases. Hence, it alone is not an alternative to the theistic explanation, but in principle there is no reason why it should not be supplemented by a biochemical theory of the origin of life from lifeless matter. No such theory has yet been completely established, but progress is being made. When and if this is done, there will be an explanation of design in living organisms for which there is empirical support, and it can no longer be claimed that theism represents the only real explanation of such facts.

what follows from the argument

The other major deficiency in Paley's form of the argument is that, even if valid, it does not go very far toward proving the existence of a theistic God. The most we are warranted in concluding is that each case of design in the natural world is due to the activity of an intelligent designer. Nothing is done to show that all cases of design are due to one and the same designer; the argument is quite compatible with polytheism or polydaemonism, in which we would have one supernatural designer for flies, another for fish, and so on. Even if there is one, and only one, designer, nothing is done to show that this being is predominantly good rather than evil; neither is anything done to show that he is infinitely powerful or wise, rather than limited in these qualities. Of course the theist might seek to supplement this argument by others, but by itself it will not bear the weight.

Argument from the Universe as a Whole

No argument that, like the Teleological Argument, is designed to show that facts in nature require a certain explanation, can establish the existence of a deity absolutely unlimited in power, knowledge, or any other respect. By such reasoning we can infer no more in the cause than is required to produce the effect. This deficiency is irremediable. However, there is a simple way of eliminating competing scientific claimsby starting from the universe as a whole rather than from individual instances of design within the universe. There are different ways of doing this. We might think of the whole universe as instrumental to some supreme goal, or we might think of the universe as a unified system of mutually adjusted and mutually supporting adaptive structures.

Taking the whole universe as instrumental to some supreme goal would give us the strongest argument, for here the analogy with consciously designed artifacts is strongest. An artifact like a house, ship, or watch is designed for the realization of goals outside its internal functioning; it is intended to be used for something. Therefore, if the analogy with artifacts is the main support for the notion that the universe was the result of conscious planning, that support would be firmest if grounds were presented for thinking that the universe as a whole was well fitted to be used for something. And if this something were of maximum value, we would then have a basis for attributing supreme goodness to the designer.

However, this alternative is rarely taken, largely because it is difficult to decide on a suitable candidate for, in Alfred, Lord Tennyson's words, the "far-off divine event, toward which the whole creation moves." The most common suggestions are the greater glory of God and the development of moral personality. But in regard to the first, no one can really understand just what it would mean for a God who is eternally perfect to receive greater glory, and in regard to the second, even if we can overcome doubts that moral development is worth the entire cosmic process, it would seem impossible ever to get adequate grounds for the proposition that everything that takes place throughout all space and time contributes to this development.

The second interpretation, that the universe is a unified system of mutually adjusted and mutually supporting adaptive structureshas been tried more often. So conceived, the argument will run as follows.

  1. The world is a unified system of adaptations.
  2. We can give an intelligible explanation of this fact only by supposing that the world was created by an intelligent being according to some plan.
  3. Therefore, it is reasonable to suppose that the world was created by an intelligent being.

The famous formulation of the argument in Hume's Dialogues makes explicit the analogy on which, as we have seen, step two depends. Hume's formulation, which is substantially equivalent to the above, runs as follows.

  1. The world is like a machine.
  2. Machines are made by human beings, in accordance with plans.
  3. Like effects have like causes.
  4. Therefore, the world probably owes its existence to something like a human being, who operates in accordance with a plan.

types of adaptation

If one is to think of the whole universe as a system of connected adaptations, he will consider kinds of adaptation other than that exemplified by the fitness of organisms to the conditions of life; this kind alone will not bear the whole weight. F. R. Tennant, who has developed the weightiest recent presentation of the teleological argument in his Philosophical Theology, discusses six kinds of adaptation:

  1. The intelligibility of the world. The world and the human mind are so related that we can learn more and more without limit.
  2. The adaptation of living organisms to their environments. This is the kind on which we have been concentrating.
  3. The ways in which the inorganic world is conducive to the emergence and maintenance of life. Life is possible only because temperatures do not exceed certain limits, certain kinds of chemical processes go on, and so on.
  4. The aesthetic value of nature. Nature is not only suited to penetration by the intellect; it is also constituted so as to awaken valuable aesthetic responses in man.
  5. The ways in which the world ministers to the moral life of men. For example, through being forced to learn something about the uniformities in natural operations, men are forced to develop their intelligence, a prerequisite to moral development. And moral virtues are acquired in the course of having to cope with the hardships of one's natural environment.
  6. The overall progressiveness of the evolutionary process.

Tennant admits that no one of these forms of adaptiveness is a sufficient ground for the theistic hypothesis, but he maintains that when we consider the ways in which they dovetail, we will see theism to be the most reasonable interpretation. Thus, the adjustment of lower organisms to the environment takes on added significance when it is seen as a stage in an evolutionary process culminating in man, which in turn is seen to be more striking when we realize the ways in which nature makes possible the further development of the moral, intellectual, and aesthetic life of man.

When the argument takes this form, it is no longer subject to competition from scientific explanations of the same facts. If our basic datum is a certain configuration of the universe as a whole, science can, by the nature of the case, offer no explanation. Science tries to find regularities in the association of different parts, stages, or aspects within the physical universe. On questions as to why the universe as a whole exists, or exists in one form rather than another, it is silent. Ultimately this is because science is committed to the consideration of questions that can be investigated empirically. One can use observation to determine whether two conditions within the universe are regularly associated (increase of temperature and boiling), but there is no way to observe connections between the physical universe as a whole and something outside it. Therefore, there is no scientific alternative to the theistic answer to the question "Why is the universe a unified system of adaptations?"

alternative explanations of adaptation

What alternatives to the theistic explanation of adaptation are there? In the literature on the subject one often encounters the suggestion that we have this kind of universe by chance. If we dismiss the animistic notion of chance as a mysterious agent, the suggestion that we have this kind of universe by chance boils down to a refusal to take the question seriously. It may be said that the fact that the universe as a whole exhibits teleological order is not the sort of thing that requires explanation. It is difficult to see what justification could be given for this statement other than an appeal to the principle that sense observation is the only source of knowledge and/or meaning.

One cannot perceive by the senses any relation between the physical universe as a whole, or any feature thereof, and something outside it on which it depends. Hence, an extreme form of empiricism would brand the question posed by the Teleological Argument as fruitless or even meaningless. If, on the other hand, the question is taken seriously, any answer will be as metaphysical as the theistic answer, for it is really a question as to what characteristics are to be attributed to the cause (or causes) of the universe. Do the relevant facts about the world most strongly support the theistic position that the cause is a perfectly good personal being who created the universe in the carrying out of a good purpose? Or is there some other view that is equally, or more strongly, supported by the evidence? The Manichaeans held that the physical universe was the work of a malevolent deity and that man must separate himself from the body in order to escape this diabolical power and come into contact with the purely spiritual benevolent deity. It has also been held in many religions that the universe is the joint product of two or more deities who differ markedly in their characteristics. In Zoroastrianism it is held that the world is the battleground of a good deity and an evil deity, the actual state of affairs bearing traces of both. Indian religious philosophy typically regards the universe as resulting from a nonpurposive manifestation of, or emanation from, an absolute unity that is not personal in any strict sense.

extent of adaptiveness in the universe

To evaluate the Teleological Argument in the light of competing explanations, we must ask whether the extent of adaptiveness in the universe is sufficient to warrant the theistic conclusion. As the problem is formulated in Hume's Dialogues, is there a close enough analogy between the universe and a machine? This requires judging the relative proportion of adaptive features to nonadaptive or maladaptive features. In addition to taking account of Tennant's enumeration of the ways in which the shape of things is instrumental to the realization of valuable ends, we must look at the other side of the picture and try to form an adequate impression of (1) the ways in which the shape of things is neutral, providing neither for good nor for evil, and (2) the ways in which the shape of things frustrates the search for value.

As for (1), as far as we can see, the distribution of matter and the variety of chemical elements in the world, to take two examples at random, could have been very different from what they are without reducing the chances of sentient beings leading satisfying lives.

As for (2), we begin to trespass onto the problem of evil, except that here we are interested in suffering and frustration not as possible disproofs of theism but as affecting the cogency of the Teleological Argument for the existence of God. There are many ways in which the organization of the world makes for disvalue rather than value in the lives of men and other sentient creatures. One need only mention the numerous sources of disease, the incidence of malformed offspring, the difficulty of attaining optimum conditions for the development of healthy personalities, and the importance of antisocial tendencies in human nature. It is quite possible, of course, that all the things that seem to be unfortunate features of the world as it exists are necessary elements in the best of all possible worlds. If we already believe that the world is the creation of a perfect deity, that carries with it the belief that these apparent evils are necessary even though we cannot see how they are. However, if we are trying to establish the existence of a perfect deity, we have to proceed on the basis of what we can see. And since, so far as we can see, the world would be better if the features listed above were altered, we cannot argue that the state of adaptiveness in the world requires explanation in terms of a perfectly good, omnipotent deity. But we have already seen, on other grounds, that the Teleological Argument cannot be used to establish the existence of a being unlimited in any respect.

The serious problem that remains is whether the total picture of adaptation and maladaptation, so far as we have it, gives sufficient support to the hypothesis that the world represents the at least partial implementation of a plan that is at least predominantly good. To resolve this problem we must weigh opposite factors and arrive at a final judgment of their relative importance. Unfortunately there are no real guidelines for this task. No one knows how much adaptation, relative to maladaptation, would warrant such a conclusion; and even if he did, he would not know what units to employ to perform the measurement. What is to count as one unit of adaptation? Do we count each individual separately, or is each species one unit? How can we compare the value of human knowledge with the disvalue of disease? It would seem that on this issue different positions will continue to be taken on the basis of factors outside the evidence itself.

See also Cosmological Argument for the Existence of God; Darwin, Charles Robert; Darwinism; Evil, The Problem of; God/Isvara in Indian Philosophy; Hume, David; Mani and Manichaeism; Ontological Argument for the Existence of God; Paley, William; Physicotheology; Popular Arguments for the Existence of God; Tennant, Frederick Robert; Theism, Arguments For and Against; Zoroastrianism.


In the Middle Ages there was general acceptance of an Aristotelian physics, according to which even purely physical processes were explained in terms of the natural tendency of a body toward an end. (Fire naturally tends to come to rest at the periphery of the universe.) Given this background, it was argued that the consideration of any natural processes led to the postulation of a designer. The argument in this form is found in Thomas Aquinas, Summa Theologiae, Part I, Question 2, Article 3. Contemporary Thomistic statements try to adjust this line of thought to modern physics. See G. H. Joyce, The Principles of Natural Theology (New York: AMS Press, 1972); Réginald Garrigou-Lagrange, God, His Existence and His Nature, 2 vols. (St. Louis: Herder, 19341936); and D. J. B. Hawkins, The Essentials of Theism (New York: Sheed and Ward, 1949).

The influential presentation by the eighteenth-century thinker William Paley is to be found in his Natural Theology: Or, Evidences of the Existence and Attributes of the Deity, Collected from the Appearances of Nature (Indianapolis: Bobbs-Merrill, 1963). Important more recent formulations include F. R. Tennant, Philosophical Theology, 2 vols. (New York, 19281930), Vol. II, Ch. 4, and A. E. Taylor, Does God Exist? (New York: Macmillan, 1947).

Acute criticisms of the argument are to be found in David Hume, Dialogues concerning Natural Religion ; Immanuel Kant, Critique of Pure Reason, Book II. Ch. 3; C. D. Broad, Religion, Philosophy, and Psychical Research (New York: Harcourt Brace, 1953); John Laird, Theism and Cosmology (New York, 1942); and J. J. C. Smart, "The Existence of God," in New Essays in Philosophical Theology, edited by Antony Flew and Alasdair MacIntyre (London: SCM Press, 1955).

William P. Alston (1967)