Key Arguments

• Parfit locates S 'between morality and the Present-aim Theory' and introduces a 'strategic metaphor' to describe its predicament as 'war on two fronts', suggesting structural exposure to attacks from both sides.
• He notes that S 'might survive attack from only one direction' but 'may be unable to survive a double attack', implying that the combined pressures of morality and P are jointly defeating.
• He observes that 'Many writers argue that morality provides the best or strongest reasons for acting. In rejecting these arguments, a Self-interest Theorist makes assumptions which can be turned against him by a Present-aim Theorist.' Thus S’s anti‑moral assumptions become ammunition for P.
• Conversely, 'his replies to the Present-aim Theorist, if they are valid, undermine his rejection of morality', so that any successful defence against P weakens his position against moral theories.
• From this dialectical structure Parfit concludes, 'I believe that this is so', asserting his view that S cannot survive this double attack.

Source Quotes

I shall advance several arguments. These can be introduced with a strategic metaphor. As we shall see, the Self-interest Theory lies between morality and the Present-aim Theory.

These can be introduced with a strategic metaphor. As we shall see, the Self-interest Theory lies between morality and the Present-aim Theory. It therefore faces a classic danger: war on two fronts.

As we shall see, the Self-interest Theory lies between morality and the Present-aim Theory. It therefore faces a classic danger: war on two fronts. While it might survive attack from only one direction, it may be unable to survive a double attack.

It therefore faces a classic danger: war on two fronts. While it might survive attack from only one direction, it may be unable to survive a double attack. I believe that this is so. Many writers argue that morality provides the best or strongest reasons for acting.

I believe that this is so. Many writers argue that morality provides the best or strongest reasons for acting. In rejecting these arguments, a Self-interest Theorist makes assumptions which can be turned against him by a Present-aim Theorist.

Many writers argue that morality provides the best or strongest reasons for acting. In rejecting these arguments, a Self-interest Theorist makes assumptions which can be turned against him by a Present-aim Theorist. And his replies to the Present-aim Theorist, if they are valid, undermine his rejection of morality.

In rejecting these arguments, a Self-interest Theorist makes assumptions which can be turned against him by a Present-aim Theorist. And his replies to the Present-aim Theorist, if they are valid, undermine his rejection of morality. Let us say that, in our view, a theory survives if we believe that it is rational to act upon it.

Key Concepts

• These can be introduced with a strategic metaphor.
• As we shall see, the Self-interest Theory lies between morality and the Present-aim Theory.
• It therefore faces a classic danger: war on two fronts.
• While it might survive attack from only one direction, it may be unable to survive a double attack. I believe that this is so.
• Many writers argue that morality provides the best or strongest reasons for acting.
• In rejecting these arguments, a Self-interest Theorist makes assumptions which can be turned against him by a Present-aim Theorist.
• And his replies to the Present-aim Theorist, if they are valid, undermine his rejection of morality.

Context

Middle of Section 47, where Parfit characterises the dialectical position of the Self‑interest Theory relative to morality and the Present‑aim Theory, preparing for arguments that jointly pressure S from both sides.