Reasons Internalism and Externalism

Whether the reasons an agent has must be grounded in their existing motivations, or can apply independently of them.

Definition

Reasons internalism (existence internalism) is the thesis that an agent has a normative reason to act only if that action could be reached by sound deliberation from the agent's existing motivations; reasons externalism denies this, holding that an agent can have reasons independent of their current motivational set.

Scope

This topic covers the dispute over the existence conditions of practical reasons. Reasons internalism, associated with Bernard Williams, holds that an agent has a reason to act only if a sound deliberative route connects the action to elements of their 'subjective motivational set'. Reasons externalism holds that some reasons apply to an agent regardless of their present desires. The topic examines Williams's argument, Korsgaard's rationalist rejoinder, and Scanlon's reasons-first externalism.

Core questions

• Must every reason an agent has connect to their existing motivations?
• What counts as a 'sound deliberative route' from motivations to action?
• Can morality supply reasons that apply regardless of what one wants?
• Are reasons more basic than desires and values?

Key concepts

• subjective motivational set
• sound deliberative route
• existence internalism
• reasons-first
• buck-passing account of value

Key theories

Internal reasons (Williams)

An agent has a reason to act only if a sound deliberative route leads from their subjective motivational set to that action; external reason claims are, strictly, false or empty.

Rationalist externalism

Korsgaard argues that the scope of practical reason is not fixed by current motivations, since rational requirements can generate new motivations, leaving room for reasons that are external to a given motivational set.

Reasons-first externalism

Scanlon takes normative reasons as primitive and irreducible, holding that facts can be reasons for an agent independently of their desires, grounding a buck-passing account of value.

History

Williams's 1981 essay 'Internal and External Reasons' set the modern terms of the debate. Korsgaard's 'Skepticism about Practical Reason' (1986) defended a Kantian rationalism against Williams, and Scanlon's What We Owe to Each Other (1998) advanced an externalist, reasons-first framework that has shaped subsequent normative theory.

Debates

The scope of practical reason

Internalists tie reasons to present motivations to avoid mysterious external demands; rationalists argue that rational deliberation itself can extend an agent's motivations, so reasons are not bounded by the current set.

Are reasons or desires basic?

Humean internalists ground reasons in desires, while reasons-first theorists like Scanlon take normative reasons as primitive and explain desires and values in terms of reasons.

Key figures

• Bernard Williams
• Christine Korsgaard
• T. M. Scanlon

Seminal works

• williams1981
• korsgaard1986
• scanlon1998

Frequently asked questions

How is reasons internalism different from judgement internalism?

Judgement internalism is about a link between moral judgement and motivation; reasons internalism is about the conditions under which an agent has a normative reason at all. One can accept either without the other.