Why You Can’t Get Morality From Reason




One of the most convincing arguments for theism (in terms of reasons cited for theistic belief) is the moral argument: if God has made us for a purpose (e.g. to love God and our neighbours) then achieving that purpose is objectively good and its opposite is objectively evil. But if we’re not made for any purpose, then there’s no objective standard to point to, to adjudicate between competing views of good and evil.

As Dostoyevsky wrote: “Without God and the future life... everything is permitted” (Dostoyevsky, The Brothers Karamasov, 589). This doesn’t mean that, without God only evil is permitted. Atheists are perfectly free to do good as well as evil. But atheists have no scriptures exhorting them to do good. If they deem something to be acceptable, then for them it is permitted, and this applies to everything.

This argument was powerfully put forward by atheist philosophers such as Nietzsche (who argued that if God is dead then we must go Beyond Good and Evil) and Hume (who argued that you can’t get a moral ‘ought’ from a scientific ‘is’). However, in recent years, new atheists such as Sam Harris (in The Moral Landscape) and Michael Shermer (in The Moral Arc) have argued that you can establish an atheistic basis for prescriptive ethics in reason and/or science. In Harris’ words:

I am arguing that science can, in principle, help us understand what we should do and should want – and, therefore, what other people should do and should want in order to live the best lives possible. My claim is that there are right and wrong answers to moral questions, just as there are right and wrong answers to questions of physics, and such answers may one day fall within reach of the maturing sciences of mind. (Sam Harris, The Moral Landscape, 28)

This is certainly a denial of Hume’s naturalistic fallacy (that you can’t get a moral ‘ought’ from a scientific ‘is’). However, asserting that science can determine human values is very different from demonstrating it. At no point does Harris demonstrate how one can get a moral ‘ought’ from a scientific ‘is’, he simply takes his culture’s oughts as given. Shermer makes a similar move in The Moral Arc:

Morality is real, discoverable, “out there” in nature, and “in here” as part of our human nature. From these facts we can build a science of morality – a means of determining the best conditions to expand the moral sphere and increase moral progress through the tools of reason and science. (Michael Shermer, The Moral Arc, 14)

The problem is that you can’t. Reason can take you from premise A to conclusion B (and it is exceedingly good at that), but it can’t justify a starting moral premise. If we can establish that X is good and Y is bad, then we can use reason to work out how to maximise X and minimise Y. But when people disagree on what’s good and what’s bad, reason and science are of no help in adjudicating between competing views. Alasdair MacIntyre’s points this out in Whose Justice? Which Rationality?:

The concept of rational justification which is at home in that form of enquiry is essentially historical. To justify is to narrate how the argument has gone so far. Those who construct theories within such a tradition of enquiry and justification often provide theories with a structure in terms of which theses have the status of first principles; other claims within such a theory will be justified by derivation from these principles. But what justifies the first principles themselves, or rather the whole structure of theory of which they are a part, is the rational superiority of that particular structure to all previous attempts within that particular tradition to formulate such theories and principles; it is not a matter of those first principles being acceptable to all rational persons whatsoever – unless we were to include in the condition of being a rational person an apprehension of and identification with a kind of history whose culmination is the construction of this particular theoretical structure. (Alasdair MacIntyre, Whose Justice? Which Rationality?, 8)

In other words, everyone thinks that they’re reasonable. No one puts forward a moral imperative for what others should do whilst conceding that they and/or their moral imperative is irrational. The mere assertion that you’re more rational than another doesn’t convince them (or anyone else) that you actually are more rational, or that your moral premise should therefore trump other competing views.

Reason and science can help us achieve that which we decide is ‘good’, but reason alone can’t adjudicate between competing moral premises (though it can certainly take each premise to its logical conclusion) and science can only tell us what ‘is’, not what we ‘ought’ to do (e.g. medical science can tell us if a certain treatment is going to save or kill, but not whether it ought to be administered on unborn children, the elderly, people suffering severe pain etc).

These insurmountable problems for establishing an atheistic basis for ethics are sometimes obscured by the term ‘secular humanism’. Secular people often adopt the values of humanism (which I’m very thankful for), but humanism doesn’t follow logically from secularism. “Man descended from apes, therefore let us love one another” is an obvious non-sequitur (it does not follow).

Nevertheless, some atheists would like to claim that it does follow, or even that it has followed in human history. In Stephen Pinker’s book Enlightenment Now, Pinker argues that humanism was essentially absent from human history until the European Enlightenment in the 1700s, in which secular reason gave birth to humanism:

The Enlightenment is sometimes called the Humanitarian Revolution, because it led to the abolition of barbaric practices that had been commonplace among civilisations for millennia. If the abolition of slavery and cruel punishment is not progress, nothing is, which brings us to the fourth Enlightenment ideal [humanism]. With our understanding of the world advanced by science and our circle of sympathy expanded through reason and cosmopolitanism, humanity could make intellectual and moral progress. It need not resign itself to the miseries and irrationalities of the present, nor try to turn back the clock to a lost golden age. (Stephen Pinker, Enlightenment Now, 11)

The problem, however, is that this is pure fiction. The Enlightenment had a complex system of causes, but they can ultimately be traced back the to the Christian Reformation in the 1500s. The Protestant doctrine of Sola Scriptura (Scripture alone) and Reformation catch cry Ad Fontes (to the sources) led people to challenge old traditions and go back to primary sources. The Christian Reformation in the 1500s (in Europe) was followed by the scientific revolution in the 1600s (also in Europe), which was followed by the Enlightenment in the 1700s (also in Europe). Few historians chalk this up to coincidence.

Unfortunately, these historical facts don’t fit the secular narrative that humanism came from secular ideas/movements, and so they’re conveniently swept under the rug. But ignoring the facts doesn’t make them go away. According to the abolitionists of slavery, they were motivated by their Christian faith, not science or reason (under certain premises, slavery is entirely reasonable). Hospitals were first established by Christians. Democracy has gone wherever Protestant missionaries have gone. And, as the secular philosopher Luc Ferry points out, human rights were advanced by Christian arguments:

By resting its case upon a definition of the human person and an unprecedented idea of love, Christianity was to have an incalculable effect upon the history of ideas. To give one example, it is quite clear that, in this Christian re-evaluation of the human person, of the individual as such, the philosophy of human rights to which we subscribe today would never have established itself. (Luc Ferry, A Brief History of Thought, 60)

It’s a very good thing that many secular people are humanists; good, that is, according to Christian values (Genesis 1:27; John 3:16). People can obviously be humanists without believing in God (as many secular people are). But, logically and historically, human rights and the values of humanism were founded on Christian assumptions and advanced by biblical argument. By contrast, there is simply no logical or historical pathway from secularism to humanism, or from reason alone to a starting moral premise. Hume was right: the rules of morality are not the conclusion of our reason.

Return to main page