1. Paul's one cheer for natural theology

St Paul's letter to the Romans is a theologically dense and complex text. Probably written in Corinth during the first five years of Nero's imperial reign (54–9) it was intended to prepare the ground for Paul's planned journey to Rome. The church there was not of his creation and nor had he previously visited it, but he recognised its commitment and potential for the spreading the Christian message throughout the empire, writing that “your faith is talked of all over the world” (Romans 1.8).Footnote ² Melancathon described the letter as a ‘summary of all Christian doctrine’Footnote ³ and although it is not a systematic treatise, Summa Doctrinae Christianae, it is comprehensive statement of Paul's understanding of the theology of redemption through the life, death and resurrection of Jesus Christ. Paul writes:

His account of Christ's death and resurrection as providing salvation to an otherwise hopeless cause, namely sinful humanity, is challenging in at least two respects. First, Paul regarded his teaching of justification and redemption through Christ as quite distinct from the ideas of the philosophers of his own and previous centuries and even as a rebuke to their wisdom. The impotence of their intellectual search is revealed in the truth that not only could they not arrive at such a teaching, but it remained unintelligible to them. As he puts it in 1 Corinthians 1.21–23: “Since in the wisdom of God the world was unable to recognise God through wisdom, it was God's own pleasure to save believers through the folly of the gospel … we are preaching a crucified Christ: to the Jews an obstacle they cannot get over, to the gentiles foolishness”.

Second, Paul directs Christians to set aside any thought that they may be saved by their own observance and good works. Only grace saves, (though through works we may co-operate with it) and grace is only available through Christ.

The first challenge must be felt acutely by a philosopher; but although Paul may have been troubled by his encounter with Epicurean and Stoic thinkers on the Athenian Areopagus (Acts 17) he was not altogether dismissive of the exercise of natural reason as a means of coming to know of the existence of God. For earlier in Romans he writes:

So notwithstanding his slighting to the philosophers, Paul also invokes the style of reasoning, familiar then and since, that argues from the character of the cosmos to its divine authorship. His words resemble a passage in Cicero's On the Nature of the Gods (Book II) in which the author sets out the consensus among members of the philosophical schools about the evidences of intelligent authorship in nature. Cicero writes:

When writing to the Romans Paul may well have been remembering similar Stoic statements. Stoicism had long flourished in Tarsus and was the established philosophy in Rome at the time of Paul's letter. In the description of his encounter with the philosophers of Athens he is reported as saying “‘since it is in him that we live, and move, and exist’, as indeed some of your own writers have said: ‘We are all his children’”. (Acts 17. 28). The first quoted phrase is from the Cretica of EpimenidesFootnote ⁵ and the second from the Phaenomena of AratusFootnote ⁶ who was certainly Stoic trained. This is not to suggest that Paul was influenced by Stoic doctrines, let alone that he was himself any kind of Stoic; indeed in the Acts case he is deploying the device of quoting sources only to reinterpret them. Yet it indicates a familiarity with philosophical natural theology and in the case of the Romans passage Paul endorses the idea, shared with Stoicism, that nature bears witness to its divine origin.

2. Natural theology in modern times

We, however, are less sure of such natural reasoning, and that fact is reflected in the intellectual insecurity of theists today. So far as the specific content of Christian theism is concerned there is also a marked lack of confidence about this; and increasingly Christians adopt an accommodationist attitude to the ways and beliefs of the world, retreating from reason into sentiment, and from faith into works. This is true both of ‘conservatives’ and of ‘liberals’: the former focussing on such issues as traditional marriage and the sanctity of life, the latter on social justice and the environment. Whatever the value of these concerns, however, Christian orthodoxy teaches that such merit as may attach to them is the work of grace, and the presentation and defence of that striking theological claim calls for intellectual nerve.

The practice of philosophically-informed apologetics is now not so prevalent as it once was, but equally the situation is better than in the middle of the twentieth century when theology had shrunk back from the often withering attacks of logical positivists and sceptical empiricists. The eighteenth century, by contrast, was a time of ambitious Christian apologetics, judged necessary by the inter-denominational disputes of the time and by the rise of deism. For while deists generally accepted the proofs of creation, they were sceptical of the claims of revelation, particularly in so far as these were said to be testified to by miracles. Christian thinkers responded by assembling the ‘evidences’ and making the case for their credibility often in forms addressed to a general educated audience. So necessary was that task judged to be that it was sometimes sponsored by individuals and corporations.

One such benefaction was the gracious endowment provided out of the will of John Hulse (1708–1790), a student of St John's College Cambridge, from which he graduated in 1728, and an ordained clergyman of the Church of England. The terms of the continuing Hulsean provision include the requirement that each year a sermon be given before the University of Cambridge on the ‘Truth and Excellence of Revealed Religion, or the Evidence of Christianity’.

Four years after Hulse's death in 1790, William Paley, of Christ's College, published a work entitled a View of the Evidences of Christianity, picking up and carrying forward a phrase that is common in eighteenth and nineteenth century Christian apologetics and which is echoed in the rubric of the Hulsean brief. More enduring than his defence of the credibility of the gospels, however, has been an aspect of Paley's foray into the field of philosophy of religion published in 1802 under the title Natural Theology; or, Evidences of the Existence and Attributes of the Deity.

Paley had a view about the relationship between these two works and their corresponding fields of revealed and natural religion, which was common through into the twentieth century. It is that captured in the expression associated with Thomistic, Roman Catholic thought, that philosophical speculation about the existence and nature of God belongs to the ‘preambles to the faith’ while reflection on Christian revelation yields the doctrine of the faith itself. Until his elevation to the Papacy, Cardinal Ratzinger was prefect of the ‘Congregation for the Doctrine of the Faith’, and one might wonder whether he might now consider founding a ‘Congregation for the Preambles to the Faith’. Such would be no bad thing, given the right staffing.

G.K. Chesterton once observed that “when a man is asked to write down what he really thinks on education a certain gravity grips and stiffens his soul, which might be mistaken by the superficial for disgust”.Footnote ⁷ Certainly in present times there is no shortage of writers who, when asked to say what they really think about ‘revealed religion’– not a term they would choose, of course – are gripped by authentic disgust and indignation, and strive to ensure that their readers do not mistake these for anything more benign.

Unsurprisingly perhaps, such critics of religious faith are typically no better disposed towards the philosophy of religion and reject arguments for the existence of God as either being fallacious or resting on false premises, or both. So, for example, Paley's reasoning from the complexity to be found in nature, in the parts and bodies of animals, for example, to the existence of a designer of nature, analogous to reasoning from the intricacies of a watch to the existence of a watchmaker, is dismissed as erroneously presuming that complexity can only be the product of design. The aim of the criticism is not confined to pointing out the logical space for uncreated order, but extends to filling that space with a real alternative, the Darwinian theory of development through natural selection on the products of random mutation. The work of the blind, and purposeless watchmaker.Footnote ⁸

Similarly, arguments from the existence of the world, conceived of as a series of contingent states or stages, to a cause of its existence, which were once standard fare within presentations of the ‘Evidences of the Existence of the Deity’, have been thought to be undermined by the idea that there is no contradiction in the notion of an infinite series of causes and effects, and hence no need to postulate a first cause at the foundation of cosmic history.

Such criticisms of the proofs of natural theology have not gone unchallenged. Some, for example, have argued that while complexity per se does not establish design, certain forms of complexity may be such that they could not be accounted for by any amount of cumulative natural selection. Alternatively it has been argued that while such levels of complexity could be so explained in principle, the actual history of life on earth is simply not long enough to have allowed for this. Likewise, some have argued that the impossibility of a series of self-sufficient causes is not to do with the impossibility of an infinite causal series but with the impossibility of the transmission of causality without there being an orginator of efficacy outside the series. Positing a ‘first cause’ on this understanding is not a matter of assigning temporal priority, but of answering the requirement for a source or font of cause and effect as such.Footnote ⁹

3. Understanding causality

Evidently the dialectical to and fro could continue, but rather than move backwards and forwards within this discussion I wish to broaden the idea of causality and of causal reasoning, which by stages will return us to the matter of grace. Paley, Hulse and others of the modern period of scientific philosophy that began in the seventeenth century and remains prominent still today thought of causality simply in efficient terms. That is to say, as a case of one thing or event bringing about another through the exercise of force, in effect the propagation of an impulse, pushing things into motion, or redirecting or arresting their motion. Certainly these sorts of phenomena do fall under the general idea of causality but they are not the only things that do so.

Imagine that as a preacher was expounding upon the ‘evidences’ of the Christian religion a small stone or a marble rolled out from under one of the pews, across the floor and came to a halt in the aisle in front of the pulpit. In wondering what caused this, one might first look to a prior event in which force was applied say by someone knocking it with his foot. But had the shape, or the material or the weight of the object been otherwise it might well have behaved quite differently. Even in taking account of such factors and of the ways in which they contributed to what happened one would not have a complete account until one knew whether the force that moved the ball was applied accidentally or on purpose. Which of these it was would have partly determined the nature of what happened. So in thinking about causality, and reasoning in terms of it, we have to go far beyond merely looking to efficient causes. We have to consider structures, material composition, weight, purpose, and no doubt other things besides. Furthermore, none of these factors is reducible to another, let alone are all of them reducible to one.

Suitably developed, reflection on the variety and distinctness of causal factors has the potential to reinvigorate traditional cosmological and design arguments to the existence of a first cause. Consider just the issue that formal or structural aspects are essential causes and cannot be reduced to efficient ones. This means that where structure appears as an effect it must be due to prior structure. So that while it may well be true that species have emerged, developed and changed through a process of natural selection this fact does not explain the source of the structures without which no such processes could occur. Without structure force is shapeless and directionless, but the formal structure and consequent intelligibility of nature are not self-explanatory. They call for explanation of a sort that simultaneously answers to their intrinsic character but also avoids further regress. Such an explanation is provided by the notion that the world expresses something of the formal structure of the mind of God.