Today we have another r/AskPhilosophy answer! Reddit user kaizervonmaanen writes:
What is Bertrand Russell’s problem with essential properties? Bertrand Russell claims that the concept of essence is “hopelessly muddled” in his History of Western Philosophy. But I have not seen him explain why that is the case in any other work he has done.
As Russell explains in his History of Western Philosophy, Aristotelian essences (which he sees as part of the package deal that comes with traditional logic) have the pernicious ambition of certifying as necessary beliefs that seem obvious but could, in fact, be mistaken. For example, the claim “all humans are mortal” seems true, and perhaps obviously. But it is not certifiable by logic alone because, logically speaking, it could be false:
…there is nothing self-contradictory about an immortal man. We believe the proposition [‘All men are mortal’] on the basis of induction, because there is no well-authenticated case of a man living more than (say) one hundred and fifty years; but this only makes the proposition probable, not certain. It cannot be certain so long as living men exist. (pp. 220-221 in this edition: https://archive.org/details/TheHistoryOfWesternPhilosophy)
In contrast, as Russell interprets him, Aristotle believed that there was a human species whose essence (or essential nature) could certify this claim. Some philosophers have held, and continue to hold, that philosophy aims at establishing necessary truths. It is often a happy accident that these necessary truths conform to our beliefs before we engage in philosophy.
In Russell’s view, the above example illustrates the vices of the traditional, Aristotelian logic with its pernicious essences, and of the traditional mode of doing philosophy wherein one seeks necessary truths that, more often than not, confirm our deeply felt convictions prior to engaging in much inquiry. They are antithetical not just to Russell’s conception of logic, and so of philosophy, but to his view as to why logic and philosophy are valuable.
For Russell, certifying the obvious, even the apparently innocent claim that all humans are mortal, is not logic’s task. Logic, at least the new logic, shows us new possibilities that may be, not old possibilities that must be. It should not dogmatize about the ‘obvious’ because this risks mistaking the obvious for the true, thereby poisoning the results of our scientific inquiry. If we are guided by a logic with its theoretically distorting essences, however, then, as he puts the point in Our Knowledge of the External World:
The logic which thus arises is not quite disinterested or candid…Such an attitude naturally does not tend to the best results. (p. 46 in this edition: https://archive.org/details/ourknowledgeofex00inruss/mode/2up)