Introduction
The central problem we address is the following: can an “ought” be derived from an “is”? During the Enlightenment, there was an attempt to ground morality solely in reason, without reference to any transcendence. But if one rejects all divine or metaphysical authority, can a strictly materialist worldview truly justify objective moral norms? We will first examine the nature and scope of Hume’s “is‑ought problem” (I), then consider its implications for an atheist morality (II). We will then analyze materialist attempts to overcome the obstacle (III), and finally reflect on the possible necessity of a metaphysical foundation to save morality (IV).
I. David Hume’s “Is‑Ought Problem”: Nature and Scope
A. Presentation of the Problem in the Treatise of Human Nature
Hume writes:
“In every system of morality which I have hitherto met with, I have always remarked that the author proceeds for some time in the ordinary way of reasoning… and then suddenly assumes the very conclusion that he ought to do, is, in effect, assumed in the premises.”
This passage highlights an illogical leap from the statement of empirical facts to normative prescription.
B. Logical Dimension of the Problem
Formally, if we assert: $$ \underbrace{\text{Is}(p)}_{\text{Fact: }p\text{ is true}} $$ we cannot deduce: $$ \text{Ought}(q) $$ without introducing an intermediate normative premise:
$$ \text{Is}(p) ,\ (\text{Is}(p) \to \text{Ought}(q)) \ \models\ \text{Ought}(q). $$
If \(p\) is true, then \(q\) ought to be done, therefore \(q\) ought to be done.
But this conditional premise already contains an “ought,” making the reasoning circular.
C. Philosophical Scope
Thus, any ethics based solely on observation (the mere description of phenomena) hits a limit: prescription cannot arise without first postulating a norm. Naturalist or positivist approaches that aim to derive morality from fact therefore remain philosophically fragile.
II. The Challenge for an Atheistic and Materialist Worldview
A. Atheism and Morality Without Transcendence
In a purely physical universe, there is neither a moral lawgiver nor any intrinsic finality. The laws of nature describe what is, not what ought to be. The absence of God leaves vacant any supreme normative authority.
B. The Temptation to Deduce Norms from Biological or Social Facts
Evolutionary ethics, for example, identifies cooperation or altruism as survival strategies. But the fact that a behavior is “natural” (e.g., kin-selective selfishness) does not make it a moral duty.
Is-to-ought error:
“Human beings seek to maximize their fitness → Therefore we must act this way”
remains invalid without an ethical axiom.
C. The Emergence of Moral Relativism
If norms arise solely from historical or biological conditions, they become contingent and subjective. Therefore, how can we claim universality for human rights or dignity? Radical atheism may lead to moral nihilism.
III. Materialist Attempts to Overcome the Problem
A. Utilitarian Ethics (Bentham, Mill)
Utilitarianism defines the criterion: $$ \text{Maximize } U = \sum_{i=1}^n u_i $$ with \(u_i\) as the happiness of individuals. But why maximize \(U\)? This obligation is not deduced from facts: it is presupposed.
B. Moral Constructivism (Rawls, Reinterpreted Kant)
Rawls proposes a veil of ignorance, Kant a pure practical reason. But reason does not invent ends; it merely organizes means. Without a terminal postulate (the good in itself), the procedure remains arbitrary.
C. Atheistic Humanist Moralism (Sam Harris, etc.)
According to Harris, science can determine what maximizes well-being. However, one must already accept that well-being is desirable, which is a non-scientific “value judgment”:
$$
\text{Science}(\text{facts})\ +\ \bigl[\text{Well-being is a good}\bigr]\ \not\implies\ \text{Ought}
$$
without a prior ethical postulate.
IV. Toward an Ethics With or Without Transcendence?
A. Reexamining Hume: Should We Despair of Morality?
Hume does not deny morality; he explains that it arises from passions rather than reason. Morality becomes expressive (emotivism) and loses its imperative character.
B. Implications for a Materialist Society
Without binding norms, every moral choice reduces to individual or cultural preferences. The risk is moral chaos, or a technocracy where costs and benefits are coldly calculated.
C. The Need for a Metaphysical Foundation to Escape the Guillotine?
For a moral “law” to be truly binding, it requires a higher authority or transcendent foundation. Either one accepts a divine legislator, or one falls back into absolute relativism. Perhaps a Platonic or Kantian moral realism (moral laws as a priori forms) could offer a compromise.
Conclusion
The “is‑ought problem” is a structural obstacle to any ethics claiming to arise solely from a description of the world. By rejecting all transcendence, the materialist view deprives itself of a foundation for moral obligation: human rights, justice, and dignity become arbitrary. The challenge, then, is to determine whether a minimal form of transcendence — whether theistic, Platonic, or Kantian — can save morality in a disenchanted universe.