Alex Rosenberg’s 2012 Argument for Nihilism
In his 2012 book, The Atheist’s Guide to Reality, Alex Rosenberg defends an argument for nihilism.[1] In this article I want to evaluate his argument.
Definitions
Before we turn to his argument, we first need to understand how Rosenberg defines his terms. Let us begin with the word “scientism.” In his own words, Rosenberg defines “scientism” as follows.
But we’ll call the worldview that all us atheists (and even some agnostics) share “scientism.” This is the conviction that [1] the methods of science are the only reliable ways to secure knowledge of anything; [2] that science’s description of the world is correct in its fundamentals; and [3] that when “complete,” what science tells us will not be surprisingly different from what it tells us today. We’ll often use the adjective “scientistic” in referring to the approaches, theories, methods, and descriptions of the nature of reality that all the sciences share. Science provides all the significant truths about reality, and knowing such truths is what real understanding is all about. (brackets are mine) (6)
As an aside, I don’t think Rosenberg anywhere shows that all atheists share the view he calls scientism; in fact, I think that’s plainly false. Suppose we adopt a so-called ‘strong’ definition of “atheism”: atheism is the belief that there is no God. How, precisely, are any of the three core beliefs of scientism supposed to follow from atheism? They don’t. A person can consistently believe both that atheism is true and that any (or all) of scientism’s three beliefs are false. For example, given the relative immaturity of the science of cosmology (compared to older disciplines such as chemistry), an atheist may justifiably doubt the claim that, when “complete,” what cosmology “tells us will not be surprisingly different from what it tells us today.” Furthermore, philosopher Thomas Nagel seems to be a prime example of an atheist who rejects scientism, as evidenced by his latest book, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False.[2] Whatever one thinks about Nagel’s book, the fact remains that not all atheists share a belief in scientism.
Next, let’s turn to “nihilism.”
Nihilism tells us … [that] moral judgments are … all wrong. More exactly, it claims, they are all based on false, groundless presuppositions. Nihilism says that the whole idea of “morally permissible” is untenable nonsense. As such, it can hardly be accused of holding that “everything is morally permissible.” That, too, is untenable nonsense.
Moreover, nihilism denies that there is really any such thing as intrinsic moral value. … Nihilism denies that there is anything at all that is good in itself or, for that matter, bad in itself. (pp. 95-97)
With definitions out of the way, let us now turn to Rosenberg’s argument.
Rosenberg’s Argument
According to Rosenberg, nihilism is “scientifically and scientistically unavoidable” (101). He claims that, “by substantiating a couple of premises, we can establish the truth of nihilism.”
* First premise: All cultures, and almost everyone in them, endorse most of the same core moral principles as binding on everyone.
* Second premise: The core moral principles have significant consequences for humans’ biological fitness—for our survival and reproduction. (101)
But how shall we evaluate Rosenberg’s claim? It isn’t clear or obvious or self-evident that those premises “establish” the truth of nihilism. So, even granting the truth of both premises, why should we think that nihilism is true? By themselves, the two premises combined do not yield a valid argument for nihilism:
(1) All cultures, and almost everyone in them, endorse most of the same core moral principles as binding on everyone.
(2) The core moral principles have significant consequences for humans’ biological fitness—for our survival and reproduction.
(N) Therefore, nihilism is true.
Notice, however, that (N) does not follow from (1): it’s logically possible that human beings have evolved a set of “core moral principles” which have significant consequences for humans’ biological fitness and which are correct. What to do?
Let’s go back to Rosenberg’s earlier claim that nihilism is “scientifically and scientistically unavoidable.” This suggests two variants of Rosenberg’s argument: a scientific and a scientistic argument for nihilism.
A Scientistic Argument for Nihilism
Here is a scientistic argument for nihilism.
(1) All cultures, and almost everyone in them, endorse most of the same core moral principles as binding on everyone.
(2) The core moral principles have significant consequences for humans’ biological fitness—for our survival and reproduction.
(3) Scientism is true.
(N) Therefore, nihilism is true.
Like the previous argument, this one is invalid. Even when we add the assumption that scientism is true, other options besides nihilism remain. Both ethical naturalism and moral skepticism are compatible with scientism.
Perhaps, however, a more charitable interpretation is to read Rosenberg as presenting an explanatory argument (really, a fragment of an inductive argument) for nihilism. We can complete the argument as follows.
Let us divide the evidence (allegedly) relevant to nihilism into background evidence and the evidence to be explained.
B: Background Evidence
1. The methods of science are the only reliable ways to secure knowledge of anything.
2. Science’s description of the world is correct in its fundamentals.
3. When “complete,” what science tells us will not be surprisingly different from what it tells us today.
E: The Evidence to be Explained
1. All cultures, and almost everyone in them, endorse most of the same core moral principles as binding on everyone.
2. The core moral principles have significant consequences for humans’ biological fitness—for our survival and reproduction.
Finally, let us define the competing explanations.
H: The Rival Explanatory Hypotheses
nihilism (N): the theory that all moral judgments are wrong and that there is no intrinsic moral value.
skepticism (S): the theory that there are true moral judgments but we cannot know which ones are true. (Note: skepticism is ontologically neutral between ethical naturalism and non-naturalism.)
relativism (R): the theory that the truth of moral judgments is relative to culture or time period.
ethical naturalism (EN): the view that moral facts and properties are nothing but natural facts and properties.[3]
ethical non-naturalism (ENN): the view that moral facts and properties are irreducible, sui generis facts and properties that cannot be further analyzed or explained.
Criteria of Adequacy
Assessment
Then we can evaluate these hypotheses according to the criteria of adequacy. Although I lack the space to defend it here, the following table summarizes my assessment of the rival explanations according to the
criteria of adequacy.
| N | S | R | EN | ENN | |
| Simplicity |  | | | |  |
| Conservativism | | | | | |
| Testability | | | | | |
| Fruitfulness | | | | | |
| Explanatory Scope | | ? | | | |
But then it becomes far from obvious that nihilism is the best explanation. On my analysis, nihilism is no better than relativism. More important, nihilism is a worse explanation than ethical naturalism!
A Scientific Argument for Nihili
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In his book, Rosenberg doesn’t explain how nihilism is scientifically “unavoidable” from his two premises. In a 2003 article, however, he (and Tamler Sommers) do offer such an explanation.[4]
Darwinian nihilism departs from [ethical] naturalism only in declining to endorse our
morality or any other as true or correct. It must decline to do so because it holds that
the explanation of how our moral beliefs arose also explains away as mistaken the
widespread belief that moral claims are true. The Darwinian explanation becomes
the Darwinian nihilist’s “explaining away” when it becomes apparent that the best
explanation-blind variation and natural selection- for the emergence of our ethical
belief does not require that these beliefs have truth-makers. To tum the Darwinian
explanation into an “explaining away” the nihilist need only add the uncontroversial
scientific principle that if our best theory of why people believe P does not require
that P is true, then there are no grounds to believe P is true.[5]
This suggests the following argument for nihilism.
(1) All cultures, and almost everyone in them, endorse most of the same core moral principles as binding on everyone.
(2) Our best theory of why people believe the same core moral principles is that such principles have significant consequences for humans’ biological fitness—for our survival and reproduction.
(3) Our best theory of why people believe the same core moral principles are binding on everyone does not require that P is true. [from (2)]
(4) If our best theory of why people believe P does not require that P is true, then there are no grounds to believe P is true.
(5) Therefore, there are no grounds to believe that core moral principles are binding on everyone. [from (1), (3), and (4)]
(N) Therefore, nihilism is true.
Although Sommers and Rosenberg describe the scientific principle in (4) as “uncontroversial,” it seems to me that the principle is false. I take “why people believe P” to mean to what we might call “extra-rational” factors such as subjective experiences, psychology, or evolutionary history. While extra-rational factors may cause a person to correctly believe P (albeit on non-rational or even irrational grounds), such a coincidence is hardly guaranteed.
In contrast, the statement, “there are no grounds to believe P is true,” implies that there are literally no grounds whatsoever to believe P is true. This belies the fatal flaw in (4): “there are no grounds to believe P is true” does not follow from the fact that “our best theory of why people believe P does not require that P is true.”
I conclude, therefore, that premise (4) is false. Accordingly, even if we grant the truth of Rosenberg’s two main premises (and, indeed, even if we assume that scientism is true), Rosenberg’s argument for nihilism, as it stands, is not successful.
Notes
[1] Alex Rosenberg, The Atheist’s Guide to Reality: Enjoying Life without Illusions (New York: W.W. Norton, 2012).
[2] Thomas Nagel, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False (New York: Oxford University Press, 2012).
[3] I take it that, contrary to Brink’s semantics, but in line with Quentin Smith’s analysis of compositional vs. identity forms of ethical naturalism, identity naturalism is the superior interpretation of ethical naturalism. See Quentin Smith, Ethical and Religious Thought in Analytic Philosophy of Language (New Haven: Yale University Press, 1997), 167-168. Cf. David O. Brink, Moral Realism and the Foundations of Ethics (New York: Cambridge University Press, 1989).
[4] Tamler Sommers and Alex Rosenberg, “Darwin’s Nihilistic Idea: Evolution and the Meaninglessness of Life,” Biology and Philosophy 18 (2003): 653-68.
[5] Sommers and Rosenberg 2003, 667.