Naturalism and the Moral Argument

One might think that if one is a metaphysical naturalist he must be a moral relativist or nihilist. Briefly, moral relativism states there are no objectively moral truths or norms that are binding on all people but rather these truths are relative to each culture and individuals. A moral nihilist goes further in saying that right and wrong are complete fictions. It’s not content to say that right and wrong are relative to each culture but rather they are complete constructs and have no objective basis in reality. Are naturalists necessarily committed to either of these two options? Well not necessarily. For example Peter Singer and Sam Harris, who authored The Moral Landscape, along with other pro-choice philosophers, are adamantly opposed to ethical relativism. They think we can know truths pertaining to what right and wrong is. How so? It is probably based on how they define knowledge. They would probably agree that the statement “Inflicting pain on a person without justification is objectively morally wrong” is objectively true. They would deny that it is only true for some people and not others.

Now Christians are also committed to the truth of this statement but for different reasons. Christians believe that it is the fact we have a certain nature – made in the image of God - that determines what we are and our value. Since natures are unalterable and our value is based on possessing that nature, our value is fixed and not determined by our experiences or functions. We can lose the ability to exercise certain functions (think, feel, etc.) and still be a person and have intrinsic value. Yes we ought not inflict unnecessary pain on others but the ability to feel pain is not the necessary or sufficient condition for being a person and having intrinsic value. We can violate someone’s rights even when they cannot feel pain at that particular moment.

So how can the naturalist be confident that we can have knowledge of moral truths? I believe that it is because he takes pain to be an essential component for constructing an ethical theory. Since animals and human beings have the ability to feel pain and we can have knowledge of experiences of pain that are connected to brain states, secularists believe they are justified in using that as a platform for constructing our ethical theories. So morality is not relative after all because it is rooted in scientific knowledge. Since scientific knowledge is objective and determines our ethical knowledge, our ethical knowledge is real knowledge insofar it conforms to our knowledge of the human brain and other factors.

And as a result of all this, the areas of life where we can acquire most, if not all, of our knowledge is by our five senses through the methods of the different sciences (chemistry, biology, physics, neuroscience, cognitive science, etc.). Anything else that falls outside of those categories might be true but would not count as knowledge.

All these factors weigh in on a controversial issue, namely abortion in different ways. First, secularism adopts a functionalist view of human persons. It is how you function, not who you are by nature, that determines whether you are a person. Metaphysical naturalism claims that the decisive factors for defining a person are things like self-awareness, experience of pain and pleasure, and a fully functioning brain. Why? It is because these are things that we can have knowledge about. We can directly access these characteristics of human beings through the methods of some scientific disciplines. We cannot detect or access any essences or natures through the sciences. So, according to these naturalistic thinkers, these things are irrelevant towards understanding what a human person looks like. Peter Singer who teaches at Princeton University has said that the capacity to feel pain is what makes us persons. And since other higher functioning animals like chimpanzees and dogs can feel pain like we do, appealing to human nature or essence to distinguish ourselves from them is arbitrary and unjustified. Human nature or essence, he says, is irrelevant towards understanding what makes you and I a person.

There are a few points one can take away from all of this. First, it seems that we as Christian apologists can bring a two-punch line approach in constructing an effective moral apologetic that would challenge the naturalist or secularist in his worldview and its impact on ethics. First, we could argue that, even though the naturalist affirms that deliberately inflicting pain on someone is objectively morally wrong – because on his view only persons who have the right brain capacity or desire not to feel pain are actual moral subjects – he cannot justify why it would be morally wrong to deliberately impair someone’s ability to be sentient and feel pain, inflict severe bodily damage on them, and kill them afterwards. This can be easily applicable to the issue of abortion. Since the unborn embryo and fetus are not considered persons via the naturalist’s definition of personhood, this act could not be objectionable since, on his view, no person with rights has yet emerged, much less been harmed. Since no moral subject has emerged, no rights have been violated and no harm has been done. What would exactly be wrong, if the naturalist is right, with operating on the fetus’ brain to prevent it from ever possessing the capacity for consciousness, self-awareness, feelings of pain and pleasure, and so on?

Lastly one could claim that a naturalistic ontology and epistemology actually undermines the ability to have moral knowledge of any sort since the possibility of moral knowledge requires the existence of immaterial, intrinsic, and universal moral norms which naturalism denies. So one could target the naturalist’s epistemological commitments and argue that his own worldview undermines any apparent objective claim to knowledge concerning moral truths. One might as well be a moral nihilist. But then again, moral nihilism is completely unlivable as a practical ethic for a stable society. So one should reject it.