Le Devoir has invited authors to use the tools of philosophy to examine contentious current events. Montreal philosophy professor, Jean Laberge (2007), tackles missionary ecologists in the wake of UN report by invoking the work of the Scottish empiricist and Enlightenment philosopher David Hume (1716-1776). Laberge based his argument on Hume’s meta-ethics, his is-ought problem.

Laberge (2007) questions the way in which Al Gore, the Pope in this fight against climate change, has turned the issue into a moral imperative. Laberge claims that according to Hume, the statement that global warming is bad is erroneous. It is a confusion between descriptive (is) and prescriptive (ought) statements. The planet is getting warmer. We cannot logically deduce from that, that humans ought to modify behaviour to diminish the impact of climate change. According to Hume’s anthropocentrism, the human faculty of reason serves human interest exclusively, not the environment. “For what does reason discover, when it pronounces any action vicious? Does it discover a relation or a matter of fact? (Hume 1739-40). Facts in themselves are value neutral. Logically, in order to decide whether something is good or bad, there must be a moral sensitivity upon which a judgment could be made. The ‘environment’ is not endowed with a moral sensitivity as humans are.

Logiquement, pour juger qu’une chose est bonne ou mauvaise, il doit y avoir une sensibilité morale à partir de laquelle un jugement de valeur peut être rendu. Or, au contraire de l’humain, l’«environnement» ne dispose pas d’une telle sensibilité morale (Laberge 2007).

In the socio-historical context in which Hume was writing he was concerned with distinguishing vulgar reasoning from true philosophy. He argued that there were four sciences: logic, morals, criticism, and politics. He claimed that morals do not result from logical reason and judgment but from tastes, sentiments, feelings and passions.

Hume distinguishes also between a vulgar [thinker who uses only common language] who proposes a system of morality and a true philosopher, between the thinking of a peasant and a true artisan. Vulgar reasoning shifts from ‘is’ to ‘ought’ imperceptibly without giving a proper explanation or producing evidence.

“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 establishes the being of a God, or makes observations concerning human affairs; when of a sudden I am surprized to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, it is necessary that it should be observed and explained; and at the same time
that a reason should be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it. But as authors do not commonly use this precaution, I shall presume to recommend it to the readers; and am persuaded, that this small attention would subvert all the vulgar systems of morality, and let us see, that the distinction of vice and virtue is not founded merely on the relations of objects, nor is perceived by reason (Hume).”

Is Laberge suggesting that Gore is a vulgar thinker who has not provided enough evidence for his case? In the case of climate change the science is overwhelmingly clear.

And humans do have the moral sensitivities which are the basis for making ethical decisions. We also have reason and scientific tools that provide us with experience-based evidence that informs our moral choices. Even Hume describes a political will, a social covenant in which citizens consult and agree upon a common ‘moral’ action.  We are not conscious of most of our mundane, everyday moral choices. Failing to protect forests or watersheds is a moral choice. A couple of decades ago most of us were insensitive to the moral nature of our actions that were destructive to ecosystems. In complex ecological issues where so many political, economics, geography, social and cultural interests converge, we consider ethical dimensions. Science can provide tools for measuring forest regeneration and efficient technologies for implementation. But science itself is not invested with moral sensitivity. It is only through human moral sensitivities that value judgments can be made in regards to unintended risks or side effects. Once science has provided evidence of shared, heightened risks we move from mere truth claims to moral justification for action or inaction.


Keywords: Hume, philosophy, epistemology, ecology, is-ought, meta-ethics,


Markie, Peter. 2004. “Rationalism vs. Empiricism.” Stanford Encyclopedia of Philosophy.

Hume, David. 1739-40. “Footnote 13.”Treatise of Human Nature.

Laberge, Jean. 2007. “Le devoir de philo: le scepticisme de Hume contre les écolos.” Le Devoir. 19 mai.