What we mean by good › Why the open question may prove less than Moore hopes

Consider a possible objection to Moore's reasoning. Two expressions could present something differently even if they refer to the same property. If so, a meaningful question about their relationship would not necessarily establish that there are two distinct properties.

The familiar comparison with water and its chemical constitution can clarify the logical point. Learning a scientific identity can be informative; it need not be a repetition of something already understood from the ordinary word. This is an illustration of an objection to the argument, rather than a claim that Moore uses the comparison in Principia Ethica.

Applied to ethics, the objection asks whether a naturalist must offer an obvious synonym for "good." A naturalist might instead propose an identity requiring substantive investigation. Moore's argument against a transparent definition would not automatically defeat that different proposal. A further argument would be needed to show that goodness cannot be natural in that way.

This objection does not establish naturalism. It identifies a gap between showing that two concepts differ in meaning and showing that their objects must differ in reality. The reader has to decide whether Moore's argument crosses that gap successfully, rather than treating the phrase "open question" as a conclusive refutation of every rival account.