The second-order property of being a rightmaking property of weight W and the second-order property of being a wrongmaking property of weight W belong to a family of mutually exclusive properties.
Second-order property(Frege's and Russell's account of existence)
A property of concepts (for Frege) or of propositional functions (for Russell), rather than a property of individuals
Wrongmaking property(as used in normative ethics)
A feature or characteristic of an action that makes it morally wrong or bad—for example, 'causing unnecessary pain' might be a wrongmaking property of an action.
weight (in ethics)(in moral philosophy)
How much a moral reason or property matters or counts—like how important it is on a scale.
But what underlies this intuitive idea? The answer is a certain very fundamental and very plausible equiprobability principle, to the effect that if one has a family of mutually exclusive properties, and if \(P\) and \(Q\) are any two members of that family, then the a priori probability that something has property \(P\) is equal to the a priori probability that that thing has property \(Q\). For then given that principle, one can consider the family of second order properties that contains the second-order property of being a rightmaking property and the second-order property of being a wrong...