The assertion that ‘God told me to do it’ has been responsible for some of the worst atrocities in history. Little has changed: almost daily our newspapers report acts of barbarism committed by those who firmly believe they are performing the will of God, which they find in the Bible, the Koran or some other sacred text, or which is revealed to them by someone expounding those texts.

The most obvious problem with the supposition that I am enacting God's will arises when other people, equally convinced that God has spoken to them, disagree with what I am doing. Examples of such disagreement are commonplace. For instance, we have all seen people from the same religion disagreeing about the status of women, or gays, or euthanasia. Each party is convinced that its view represents God's will, and is equally convinced that those espousing the opposite view have got it wrong. Moreover, there is no agreed way of settling the argument. If, say, the disagreement is within Christianity, one might suggest that closer study of the Bible should reveal a more accurate interpretation of God's will. However, even experts who have studied the Bible all their adult lives disagree with each other on the interpretation or application of various texts, so further study will avail little.

There are, of course, those who espouse a certain view because they claim that God has spoken to them directly. Given that somebody else will make exactly the same claim while espousing the opposite view suggests that such claims should be taken with a grain of salt. At the very least they require some form of verification, ergo the appeal of scripture.

Part of the problem appears to be that people interpret sacred texts to suit their own ideas, and that the texts are variegated enough to support almost any interpretation. For example, some years ago I listened to a sermon in which the vicar argued, very persuasively and logically, that apartheid was supported by the Bible. The next Sunday I attended a different church and listened to an equally compelling sermon that argued precisely the opposite.

The real problem, however, is not about the interpretation of texts and/or our willingness to read any number of harebrained ideas into scripture. No, the real problem is the assumption that God can speak to us at all. If you don't believe in God you might think this is a spurious problem and not worth thinking about, but you would be wrong. After all, any one of us – believer or unbeliever – could be confronted by, or even be the victim of, somebody who at the very least believes that God can communicate with human beings.

In my view the best counter-argument to this belief comes – albeit indirectly – from the philosophy of Ludwig Wittgenstein (1889–1951). In a discussion about whether we can know what other people are thinking or intending, Wittgenstein states, ‘If a lion could talk, we wouldn't be able to understand it’.Footnote ¹ His assertion has nothing to do with the problems of communicating with large felines. Rather, Wittgenstein's point is that to communicate at all, let alone discern somebody else's thoughts or intentions, we must have a great deal of behaviour in common. Using language is a – and probably the – fundamental human activity, and language is embedded in the lives of those who speak it. The structure and functions of language are intrinsically linked to the structure and functions of the whole complex of human activities from which it arises and which it facilitates. In other words, language is an intrinsic part of our huge, shared cultural landscape and it cannot work, let alone be understood, apart from that landscape. Language cannot, for example, be extracted from that landscape in an attempt to understand it as an artefact in and of itself. Any attempt to do so would be like trying to describe a great painting by referring only to the wavelengths of light reflected by the various blobs of colour.

Further, if language cannot be extracted, or understood apart, from its cultural context then it follows that it cannot be imposed on us from outside that context. It cannot in any sense be thought to descend from heaven. If it were, we would not be able to understand it. Wittgenstein's lion cannot speak to us because it does not share any of our cultural landscape. Moreover, insofar as we have no cultural behaviour in common with a lion, not only is linguistic understanding impossible but also there is nothing to communicate. We could embellish Wittgenstein's assertion by stating that we could not understand the lion and it would have nothing to say to us anyway.

It is important to note that none of the above means we cannot communicate with animals. Anybody who owns a domestic animal – I have, or rather serve, two cats – is well aware of their ability to communicate what they want and when they want it. This, however, is not language. My cats can tell me they want their dinner or want me to move their beds into the sun, and I can call them to breakfast or to be brushed, but they know nothing of irony or aesthetic appreciation or telling lies, and I cannot talk to them about my situation at work or my worries about paying the mortgage.

However, we can learn languages, so couldn't we learn ‘lion language’ in much the same way as, say, an archaeologist learns a newly discovered and hitherto unknown language? No, because we are able to interpret, and even eventually learn, the lost language only through reference to our shared human behaviour. In other words, the people who spoke this language had to feed themselves, care for their families, build dwellings, manage conflict and so on, and their language arose from and was an intrinsic part of those activities. We share none of this behaviour with a lion. Of course, lions also feed themselves, and insofar as we have this biological necessity in common then it might be argued that we have some shared behaviour. However, a moment's thought will reveal the cultural and behavioural chasm between a lion's feeding and a person's eating. Our growing, selection and preparation of food all involve complex behaviours and rituals, and our sharing of food is even more complex. We share none of those behaviours and rituals with lions or any other animal.

If, then, an animal cannot speak to us, what about God? After all, some people say that God speaks to them through their holy books, or even through nature, and there are plenty of places in the Bible where the text unambiguously states, ‘Thus says the Lord’. However, if a lion cannot speak to us, much less can God. We share no culture or behaviour with a lion, but at least we can inhabit the same physical landscape, share the same climate, and have in common some basic physical feelings like hunger and thirst. We have not even that little in common with God. In other words, the fundamental conditions for language – for communication using words, whether spoken, written or using any other medium – are absent from any relationship we could possibly have with God. This is not to say that a person cannot feel inspired, loved, forgiven, empowered or vindicated by God, but God cannot say as much to that person.

Part of the problem is that our concept of language is awry. We tend to think of language as the medium through which the mind of one person is revealed to another. According to this view, language ‘encodes’ our thoughts and we can thereby communicate what is in our mind to another person. Language therefore involves two processes: an inner – our thoughts – and an outer – our speech. A moments reflection, however, should reveal the limitation of this view. Though occasionally I might form a sentence in my mind before I speak, most often I just speak it. There are not two processes in operation; rather, there is just one process of speech. If I say, ‘It's raining’, I am not expressing a thought behind the words, nor would the person to whom I speak say, ‘These are just your words, so I have to get behind the words to find out what you really mean’. Indeed, if my interlocutor thinks there is more to my statement than a simple weather report then this will not have arisen from her assessment of my thoughts but rather from her observation of my ‘body language’ and facial expression and from the tone of my voice. If my posture slumps and my face and voice both express regret, she will immediately respond, ‘I can tell you are disappointed that it's raining’. Indeed, she will probably discern my disappointment more quickly and accurately than I can enunciate it, or even before I have admitted it to myself. The point is that even if, for argument's sake, we allowed that God could communicate to us though words – through scripture, for example – we would nonetheless lack all the other vital ingredients – facial expression, posture, intonation and so on – that facilitate and enrich our communication with each other.

Moreover, even if language occasionally encodes thought, this is of no help at all when considering communication from God. As we have seen, language works to the extent that interlocutors share a linguistic landscape. However, the qualities that differentiate God from human beings – omniscience and omnipotence to mention only two – are the same qualities that segregate our linguistic landscapes. If God is all-knowing, for example, then there is no meaningful sense by which a finite human being can know God's thoughts, much less share a form of life in which God and human beings can communicate. After all, the unbridgeable linguistic distance between us and a lion is vastly less than that which separates us from God.

Some might argue that since God is capable of doing anything, he could therefore communicate with us if he wanted to. However, this argument clearly backfires because to the degree it appeals to God's omnipotence it makes God even more remote. Consider a parallel example. Human beings can communicate in various ways with some of the ‘higher’ animals – such as cats and dogs – but cannot communicate with ’lower’ forms of life – such as insects. The point is that our relationship to God much more closely parallels the immense distance that separates us from insects than it does our comparatively small separation from higher animals.

We have noted that language makes sense only within a certain social context. For example, if I go to a building supplies store and ask for two dozen one-inch brass self-tappers, the man behind the counter does not have to wonder about the meaning of my request. Indeed, while he is handing over my order he may be speaking to a colleague about his recent holiday or what he is going to have for lunch. The purpose of my words is not to convey a meaning but rather to elicit a response, and my request makes sense only within a certain context in which the participants share conventions about number, measurement, object identification, commercial transactions and so on. If I were to use the same words in a different context – during a church service, for example – they would make no sense and elicit no response, except perhaps that other worshippers might speculate about my sanity.

We can see from this that language functions as a tool, and that this tool works only in appropriate social contexts. Moreover, those contexts are themselves the product of long and often complex trajectories of human activity. My above request for brass screws is very straightforward, but the context in which it makes sense is the culmination (and combination) of very complex and variegated social activities. If, then, God spoke to us, in what social context could his words make sense and elicit a response? There exists no such context because there are no social trajectories in which God had any participation that is even remotely comparable to human participation.

Consider, for example, the divine command to ‘love your neighbour’. Any command makes sense only in a context in which one party can command and the other party must (or at least should) obey. This apparently simple context is actually extremely complex. If, for instance, my boss asked me to pick up her dry cleaning during work hours, I would do so because her command makes sense within the context of certain workplace agreements, individual contracts and so on. If, though, she asked me to do so outside of work hours, then this would not constitute a command but rather a special favour in return for, say, time in lieu. The point, again, is that commands make sense only within shared social contexts of great complexity. None of this applies to divine commands: there is no shared social context in which the participants inherit a trajectory within which the relationship between commands and responses has been developed.

Indeed, the concept of a divine command makes sense (if it does at all) only because it echoes human commands. The point is not, however, that the parallels between human and divine commands allow us to understand the latter. It is, rather, that divine commands are actually a special type of human command, and that they make sense because of a long historical trajectory of commands imputed to divine beings through all-too-human agencies. Indeed, divine commands make sense only insofar as they are human commands, and only within specific social contexts.

Let us return to Wittgenstein's lion. If comprehensible words somehow began to tumble from its mouth then we could be certain, despite any appearance to the contrary, that a human being was speaking. If anybody claims that God is speaking to them or through them then we may also be certain that not only is a human being speaking but also one who realises that his (it is usually a man) message is sufficiently irrational and repellent as to need divine authorization. In short, divine language can be ‘heard’ only by those who have the hubris to equate their own self-interest and self-aggrandisement with speech from God.