Of the sensus divinitatis Introduction

The focus of this chapter is Reformed theologian Alvin Plantinga’s version of the sensus divinitatis (Plantinga 2000), purportedly an innate human faculty whereby we gain knowledge of God. Plantinga has developed his model based on comments made by Thomas Aquinas and John Calvin, and given that he not only is a Christian exclusivist (Plantinga 1995), but also argues against natural-ism in general and evolutionary theory in particular as offering a coherent account of our rational faculties and why we may depend on them (Plantinga 1993b), it might seem perverse for the current enquiry to draw upon his

thinking. However, I will be arguing in due course that a modified version of his model of the sensus divinitatis can provide a crucial link between spirituality (particularly the “vertical” component) and evolutionary theory. The modific-ations I propose to make take into account not only the pluralist contention that non-theistic construals of the transcendent Real are as valid as theistic

construals, but also the insights offered by evolutionary theory into human nature and our cognitive architecture.

There are numerous historical sources for the idea that we have an inbuilt capacity or faculty for an awareness of God (Holland 2007: 765 n2). Cicero praised Epicurus for perceiving “the existence of the gods on the impression which nature herself hath made on the minds of all men”, and he infers that,

“since it is the constant and universal opinion of mankind, independent of education, custom, or law, that there are gods, it must necessarily follow that this knowledge is implanted in our minds, or rather is innate in us. That to which there is a general agreement through nature must infallibly be true; therefore it must be allowed that there are gods” (Cicero 1829: 26, 27).

Cicero’s logic can certainly be challenged, since a universal belief in some-thing is not evidence for its truth (it could be a universal false belief); neverthe-less, his argument that nature has “implanted” in humankind an idea of the gods is an early counter to “blank slate” models of human nature whereby the human mind is believed to be empty or blank until experience, and experience alone, gives it content (Pinker 2002).

Zoroaster used a term which “in effect postulates and designates a religious faculty in man” (Smith 1991 [1962]: 99); and Augustine of Hippo’s plaint that

“Thou awakest us to delight in Thy praise; for Thou madest us for Thyself, and our heart is restless, until it repose in Thee” (Augustine 1907 [397]: 1) implies

the existence of an inbuilt ability or faculty of responding to God which needs activating or “awakening”.

Aquinas suggests in Summa Theologiae that “[t]o know in a general and confused way that God exists is implanted in us by nature” (quoted in Plantinga 2000: 170), and Calvin (1931 [1536]) uses the concept of innate knowledge of God derived from the operation of the sensus divinitatis as part of his argument that we humans cannot plead ignorance of God and his commandments as an excuse for our wrong-doing. We pick up on Aquinas and Calvin below.

Writing roughly a century after Calvin, Lord Herbert of Cherbury (regarded as the “father of deism”) argued that human beings are endowed with a relig-ious sense that accounts for religion’s very existence (Preus 1987), and the 18^th century New England divine Jonathan Edwards proposed a supra-physical

“sense of the heart” which entails the perception not only of the fact of the

“infinite excellency of God”, but also “a perception of meaning and value” (Hay 1987: 80). In the 20^th and 21^st centuries, Ernst Troeltsch refers to “the religious apriori within the human spirit – the innate orientation toward and the experi-ence of the divine built into human nature” (Knitter 1985: 25); Rahner (as dis-cussed in the previous chapter) referred to a “pre-reflective, pre-apprehension of God… which [he] calls ‘transcendental revelation’” (D’Costa 1986: 81);

William Alston (1991) has developed the idea of “Mystical Perception” providing information about God which is on a par with knowledge of the external world provided by our sense perceptions; and Ian Markham in his critique of the “new atheists” refers throughout to the “spiritual sense” (Markham 2010: 4 and

passim). But the name currently most associated with developing the idea of the sensus divinitatis is Alvin Plantinga, and to his ideas we now turn.

Alvin Plantinga and the sensus divinitatis

The sensus divinitatis purportedly delivers not simply belief in but knowledge of God, so one of Plantinga’s necessary tasks is first to demonstrate how a belief can constitute knowledge. I believe many things, and I know many things (I believe), but although what I believe and what I know are (probably) over-lapping, they are not automatically coterminous sets. I know I am Richard Skinner. I know I like eating bananas. I know Mount Everest is about 29,000 feet high… or do I? I certainly believe Mount Everest to be about 29,000 feet high, but do I know it? Well, I remember reading years ago that it had been

measured at exactly 29,000 feet but because that sounded too neat they had added on a couple of feet (heavy snowfall?), and I have checked Everest’s reported height in an atlas, on-line in Wikipedia, and in my copy of Curious Facts for Curious Boys which all pretty much concur, give or take a blizzard. So I am relying on memory and the testimony of others. But still, despite consulting these sources, can I truly claim to know the height of Everest? Is it knowledge that I have, or just a firm belief? Suppose tomorrow a reputable geographer announces that new measurements and calculations have revealed Everest to have been over 31,000 feet high for many centuries? Suppose over the

following weeks all other reputable earth scientists, having examined the evidence, announce their support for this revised information – then my belief that Everest is 29,000 feet high vanishes, so it can’t have been knowledge in the first place. What I had had knowledge of, maybe, was that the official consensus had been that Everest was 29,000 feet high, but that consensus was (it now appears) wrong. Their belief was wrong, and therefore so was mine. I (and they) had had a belief, but it wasn’t knowledge.

This might seem an arcane point, typical of philosophers who would starve if they had to decide before eating a meal that they know rather than simply believe (or hope) that the (alleged) eggs and (putative) bacon in front of them are nutritious not poisonous, but it is important when it comes to the contentious area of belief and knowledge concerning God or, more broadly, the Real.

When, if ever, does theistic belief count as knowledge of God? When, if ever, does belief in, or about, the Real, count as knowledge of a transcendent domain (realm, dimension, aspect of our total environment)?

In tackling this, two key terms in Plantinga’s epistemology need addressing, namely “proper function” and “warrant” (Plantinga 1993b), both necessary for an understanding of whether a particular a belief arising through the operation of a cognitive faculty or module (including the sensus divinitatis) can constitute actual knowledge. Although Plantinga (1993a, 1993b, 2000) writes at length about them, here only a brief outline is possible in which much of Plantinga’s subtlety is lost, but it will be sufficient for the purposes of the current enquiry.

Proper function

For the formation and deliverance of beliefs, we need to have “epistemic faculties that function properly… A belief has warrant for you only if your

cognitive apparatus is functioning properly, working the way it ought to work, in producing and sustaining it” (Plantinga 1993b: 4). “Proper function” refers to the operation of a mechanism (or indeed a biological organ) which is carrying out the function for which it is designed. The proper function of car brakes is to slow the car when the brake-pedal is depressed; the proper function of a clock is to depict accurately the passage of time; and so on – and it seems pretty well self-evident that the proper function of an artefact is simply that which the artefact is designed to do, and similarly it is easy to specify, at least roughly, when it is malfunctioning, namely when it is not performing the function for which it is designed.

We also speak quite happily of the function of biological organs: the function of the heart is to pump blood round the body, the (or a) function of the kidneys is to keep the blood clean and chemically balanced; and “the fact that these organs are supposed to do these things, the fact that they have their functions, is quite independent of what we think they are supposed to do. Biologists discovered these functions; they didn’t invent or assign them” (Dretske, quoted in Plantinga 1993b: 5).

However, the notion of proper function applied to a biological organism is more problematic. It is hard to argue, for example, that an oak tree in itself has a proper function. It just is. Yes, it might function within the entire ecosystem to, say, help maintain the oxygen in the atmosphere, but it is pushing it to claim that helping maintain the oxygen balance is its proper function, that for which it was designed. As Plantinga puts it: “What is it… for a natural organism – a tree, for example, or a horse – to be in good working order, to be functioning

properly, to be functioning the way it ought to, to be functioning in accord with its design plan? Isn’t a trout decomposing in a hill of corn functioning just as properly, as far as nature herself goes, as one happily swimming around chasing minnows?” (Plantinga 1993b: 195 – emphasis in original).

Plantinga is making the counter-intuitive point that in the absence of what he calls a “design plan” one cannot talk about something having a “proper

function”, for a proper function of something is the function specified for it according to the design plan. And although we might consider that a decomp-osing trout is not functioning properly as a trout, it is, as it were, “functioning”

perfectly well in its capacity as a dead trout – it is decomposing according to the natural laws that govern the fate of dead organisms in general. Decompose is

what – it could be argued – dead organisms are supposed to do. This argument cannot plausibly be applied to artefacts. It doesn’t work to say that a broken car brake is functioning perfectly well as a broken brake, for that is to miss the point that the brake was designed to slow the car, and failing-to-slow-the-car is not part of the design specification of car brakes, there is no design plan for a

“broken brake” (cynical built-in obsolescence aside).

Although artefacts such as car brakes do have a design plan, it is contenti-ous to claim that a biological organism has a design plan – this is the area of

“special creation” of the species; and indeed the so-called “argument from design” supporting belief in the existence of a God received a severe blow from Darwinism, with God as the designer of organisms being ousted by the “blind watchmaker” of natural selection (Dawkins 1986) which works to no design plan by which the functioning of the organism can be judged. Hence, Plantinga’s argument goes, there is no “proper function” of organisms if one takes a naturalistic stance, whereas a theistic stance which entails a creator God who has divine purposes in mind for his creatures – and hence, as it were “design plans” for them – supports the concept of “proper function” being applicable to natural entities as well as artefacts. From a theistic perspective, the proper functioning of (say) a human being would be (in general terms) that human being functioning as God intended.

This argument that “proper function” cannot be applied to biological organisms if one adopts a naturalistic stance is part of Plantinga’s argument against naturalism and in favour of theism; but for the purposes of the current enquiry it is not necessary to expand on this here. All we need for now is the concept of the “proper function” of some entity being its functioning according to its design. The question of whether or not an organism can be said to have a proper function when it is viewed through the naturalistic lens of evolutionary theory is important, and will be further considered later (p 222), but the relevance now is that the “proper function” of our cognitive faculties is an essential element in deciding whether or not our beliefs have warrant.

Warrant

“Warrant” is Plantinga’s answer to the epistemological questions: “what is it that distinguishes knowledge from mere true belief? What further quality or quantity must a true belief have, if it is to constitute knowledge?” (Plantinga 2000: 153).

On the face of it, these are odd questions, but it is fairly easy to dream up scenarios in which someone can have a belief that happens to be true, but which cannot really be deemed knowledge because the grounds for that belief are suspect or downright illegitimate. Plantinga gives the example of an

optimistic mountaineer who believes the weather tomorrow will be good for climbing despite terrible forecasts. As it turns out, the forecasters are wrong and the weather is ideal, but although the mountaineer’s belief that the weather would be good was true “it didn’t constitute knowledge” (Plantinga 2000: 153) – it was simply optimism that struck lucky. However, this example might be

considered unconvincing since someone “believing” the weather will be good tomorrow is not claiming that belief to be definite knowledge – it is an

expression of hope or expectation. A clearer example would be my belief that the summit of Ben Nevis is roughly 4409 feet above sea level, a belief based on your say-so (without my referring to other sources of information, not even Curious Facts for Curious Boys), and which is a justified belief because I know you are extremely knowledgeable, you have never lied to me, and I am not aware of any reason why you should suddenly start lying, so I am justified in accepting your statement. But unknown to me mountain heights is your one area of ignorance, and not wishing to admit your ignorance you pluck a figure out of a book of random numbers, alighting on the right answer by sheer luck;

so my consequent belief about the height of Ben Nevis happens to be a true belief, but was acquired by means that denies it the status of knowledge.

Gettier (1963) famously proposed other equally (or even more) implausible but logically possible scenarios, but their implausibility does not invalidate the conclusion that it is possible for someone to hold a true belief, and be justified in holding that belief, but under circumstances that deny that belief the status of knowledge.

What is needed to convert justified true belief into actual knowledge is, according to Plantinga, warrant, namely “that further quality or quantity

(perhaps it comes in degrees), whatever precisely it may be, enough of which distinguishes knowledge from mere true belief” (Plantinga 2000: 153), and for a true belief to have warrant, and thus to count as knowledge, Plantinga argues that a number of conditions have to be satisfied.

First, one’s cognitive faculty, through the operation of which one has come to have this belief, needs to be “functioning properly, subject to no disorder or

dysfunction” (Plantinga 2000: 153 – emphasis added), not impaired by, say, too much alcohol or organic brain disease. Hence the belief of the man who

mistook his wife for a hat (Sacks 1985) was unwarranted because his cognitive faculties, disturbed by a neurological disorder, were not carrying out their proper function.

Second, there has to be a design plan for the cognitive faculty – that is, a way in which it is supposed to work so that, by comparison with which, it is possible to determine whether or not the faculty is indeed functioning properly:

“[h]uman beings and their organs are so constructed that there is a way they should work, a way they are supposed to work, a way they work when they work right; this is the way they work when there is no malfunction” (Plantinga 2000: 154 – emphasis in original). Briefly, then, the cognitive “organ” or faculty by which a particular belief comes into existence needs to be working as it was designed (“by God or evolution” [2000: 155]) to work.

Third, the design plan for the cognitive faculty has to be “a good one, one that is successfully aimed at truth” (2000: 156 – emphasis in original) – which may seem self-evident, but it is logically possible for the cognitive faculty to be aimed not at truth but at usefulness. There are cases “where the design plan is not aimed at the production of true… beliefs but at the production of beliefs with some other virtue” (1993b: 16), such as someone whose belief that they will recover from a disease is not justified by the statistics, but which actually functions to improve their survival chances, hence the purpose of the cognitive faculty under those circumstances “is not to produce true beliefs. [It is] instead aimed at something else: survival” (1993b: 13). Thus our cognitive faculties may be functioning perfectly well according to their design plan, yet deceive us.

This distinction between a truth-directed faculty and a usefulness-directed faculty will arise again later on in connection with evolution, in which the processes of natural selection, it can be cogently argued, operate on what works rather than what is true (Ruse 2006), a distinction Plantinga uses to argue against naturalism – “natural selection isn’t interested in true belief, but in adaptive behavior” (Plantinga 2000: 231).

Fourth, the environment needs to be appropriate for the functioning of the cognitive faculty in question, i.e. that in which it has been designed to operate – if, for instance, one is subjected to extremes of temperature, as on a long trek across the Arctic, one’s cognitive faculties will be deleteriously affected (Geiger

2009), and beliefs we acquire under such circumstances (such that there is a mysterious extra person in the party) lack warrant because the cognitive faculties are trying to work outside their designed-for range.

In summary, according to Plantinga a belief has warrant for someone “only if that belief is produced in [them] by cognitive faculties functioning properly

(subject to no dysfunction) in a cognitive environment that is appropriate for [their] kind of cognitive faculties, according to a design plan that is successfully aimed at truth” (Plantinga 2000: 156). It should be noted that, curiously, even a false belief can have warrant if it “is produced… by cognitive faculties success-fully aimed at truth and functioning properly in an appropriate environment”

(1993b: 55); but if it is a true belief that has warrant, then it constitutes knowledge.

The sensus divinitatis: Aquinas/Calvin model

Both proper function and warrant are necessary factors in the model of the sensus divinitatis faculty as Plantinga develops it. This faculty, according to him, is part of our “epistemic establishment” (1993b: 48), that set of cognitive modules we have which produces beliefs on a wide range of topics such as

“[o]ur everyday external environment, the thoughts of others, our own internal lives… the past, mathematics and logic, what is probable and improbable, what is necessary and possible, beauty, right and wrong, our relationship to God, and a host of other topics” (1993b: 42). The modules involved include those pertaining to “self-knowledge, memory, perception, knowledge of other persons, testimony, a priori knowledge, induction, and probability” (1993b: 48), each of which is responsible for delivering beliefs – my belief, for instance, that the Battle of Hastings was in 1066 comes through the testimony of others (I cannot know or have beliefs about such an historical event through direct participation)

“[o]ur everyday external environment, the thoughts of others, our own internal lives… the past, mathematics and logic, what is probable and improbable, what is necessary and possible, beauty, right and wrong, our relationship to God, and a host of other topics” (1993b: 42). The modules involved include those pertaining to “self-knowledge, memory, perception, knowledge of other persons, testimony, a priori knowledge, induction, and probability” (1993b: 48), each of which is responsible for delivering beliefs – my belief, for instance, that the Battle of Hastings was in 1066 comes through the testimony of others (I cannot know or have beliefs about such an historical event through direct participation)