Key Arguments

• Parfit presents this as 'a further ground' for revision beyond the internal, promise-based argument for R: 'There is a further ground for thinking that we ought to revise Common-Sense Morality.'
• He stresses that Chapter 3’s diagnosis of the Second Mistake did not assume Consequentialism: 'Chapter 3 showed this to be a mistake. And, in showing this, I was not assuming Consequentialism.'
• He claims that even non-consequentialists should accept that some cases require attention to what we together do: 'Those who reject C would agree that, in some of my examples, we should not ignore the effects of what we together do.'
• He underlines that the mistake claim applies regardless of one’s stance on Consequentialism: 'We must agree that this is a mistake even if we reject C and accept Common-Sense Morality.'
• He also notes that earlier argumentation provided 'a sense in which our morality itself tells us to accept this revised version of itself', suggesting that the push towards R arises from within Common-Sense Morality once these considerations are acknowledged.

Source Quotes

R. This provides a sense in which our morality itself tells us to accept this revised version of itself.59 There is a further ground for thinking that we ought to revise Common-Sense Morality. This moral theory makes what I called the Second Mistake in moral mathematics.

It ignores the effects of sets of acts—the effects of what we together do. Chapter 3 showed this to be a mistake. And, in showing this, I was not assuming Consequentialism. Those who reject C would agree that, in some of my examples, we should not ignore the effects of what we together do.

And, in showing this, I was not assuming Consequentialism. Those who reject C would agree that, in some of my examples, we should not ignore the effects of what we together do. Common-Sense Morality ignores these effects whenever it is directly collectively self-defeating.

In such cases it is a mistake to think that what matters morally are only the effects of what each person does. We must agree that this is a mistake even if we reject C and accept Common-Sense Morality.

Key Concepts

• This provides a sense in which our morality itself tells us to accept this revised version of itself.
• There is a further ground for thinking that we ought to revise Common-Sense Morality.
• Chapter 3 showed this to be a mistake. And, in showing this, I was not assuming Consequentialism.
• Those who reject C would agree that, in some of my examples, we should not ignore the effects of what we together do.
• We must agree that this is a mistake even if we reject C and accept Common-Sense Morality.

Context

Same passage in Section 39, immediately after Parfit has argued (in earlier lines) that, in communicative Parent’s Dilemmas, Common-Sense Morality’s own principles direct us to adopt R; here he adds an independent, non-consequentialist-dependent reason to revise Common-Sense Morality, namely its commitment to the Second Mistake in moral mathematics.