You alleged twice that Grandpierre misrepresented Pinker. I disagree and observe that Grandpierre drew the conclusion from Pinker’s statement that in “other words, moral reasoning assumes the existence of things that science tells us are unreal.”
I leave it to the Lurkers to decide whether Grandpierre misrepresented Pinker:
In How the Mind Works, MIT professor Harold Pinker argues that the fundamental premise of ethics has been disproved by science. "Ethical theory," he writes, "requires idealisations like free, sentient, rational, equivalent agents whose behaviour is uncaused." Yet, "the world, as seen by science, does not really have uncaused events." In other words, moral reasoning assumes the existence of things that science tells us are unreal (Pearcey, 2000). These formulations demonstrate that in practice scientific materialism is a monist view ignoring completely the autonomy of any other ontological levels.
"science and ethics are two self-contained systems played out among the same entities in the world... Free will is an idealization of human beings that makes the ethics game playable. Euclidean geometry requires idealizations like infinite straight lines and perfect circles, and its deductions are sound and useful even though the world does not really have infinite straight lines or perfect circles. The world is close enough to the idealization that the theorems can usefully be applied. Similarly, ethical theory requires idealizations like free, sentient, rational, equivalent agents whose behavior is uncaused, and its conclusions can be sound and useful even though the world, as seen by science, does not really have uncaused events. As long as there is no outright coercion or gross malfunction of reasoning, the world is close enough to the idealization of free will that moral theory can meaningully be applied to it. ...
Science and morality are separate spheres of reasoning. Only by recognizing them as separate can we have them both."
This paper defuses the seeming threat of naturalistic materialism to morality, using some passages from MIT cognitive scientist Stephen Pinker's How the Mind Works as a target. Pinker, like his colleague Marvin Minsky, supposes that we must "idealize" ourselves as uncaused creatures in order to have morality. That is, he thinks we must pretend to have free will, even though science shows we don't. Naturally, and naturalistically, I take issue with this and try to show that we need not compartmentalize science and ethics. I suggest that this is not merely an academic issue, but has real world consequences for how we approach social deviance and destructive behavior. This essay appeared originally in the Humanist; see The Science of Stigma for an abbreviated version of this argument.
Pinker, however, states that free will and ethical reasoning are as real as mathematical concepts. Their causation and "reality" are irrelevant to their usefulness.
The difference may be too subtle, but it's significant.