The is-ought problem challenges the idea that moral obligations can be derived solely from facts about the world. This fundamental gap between descriptive and prescriptive claims has significant implications for how we justify and ground our ethical beliefs.

Moral motivation explores whether our moral judgments necessarily lead to action. Internalists argue for a necessary connection between moral beliefs and motivation, while externalists see this link as contingent, raising questions about morality's practical relevance.

Hume's Is-Ought Problem

The Logical Gap Between Descriptive and Prescriptive Claims

• Hume argued prescriptive moral statements (ought claims) cannot be logically derived from purely descriptive premises (is claims)
• This is known as the is-ought problem or Hume's Guillotine
• The is-ought problem challenges the possibility of grounding morality in empirical facts about the world
• It suggests a fundamental logical gap between descriptive and normative domains

Implications for Moral Epistemology and Justification

• If the is-ought problem holds, moral principles cannot be justified solely by appealing to factual statements about how the world is
• Additional normative premises are required to bridge the gap
• The is-ought problem has significant implications for moral epistemology
  • It questions how we can have knowledge of objective moral truths if they cannot be derived from empirical facts alone
• Hume's challenge has shaped much of subsequent moral philosophy
  • Many theories attempt to bridge the is-ought gap or argue for alternative foundations for ethics (divine command theory, social contract theory)

Deriving Moral Obligations

Naturalistic Theories and Evolutionary Ethics

• Naturalistic theories in ethics attempt to define moral properties in terms of natural, scientifically observable properties
  • For example, utilitarianism defines the good in terms of pleasure or well-being
• Evolutionary ethics argues moral intuitions and behaviors have an evolutionary origin
  • They were shaped by natural selection to promote survival and reproduction
  • Critics argue this commits the naturalistic fallacy by reducing the normative to the descriptive
• Attempts to naturalize ethics often face challenges in fully bridging the is-ought gap
  • Critics argue they inevitably smuggle in implicit normative assumptions at some point in their reasoning

Intrinsic Moral Facts and Social Contract Theory

• Some philosophers have argued certain facts intrinsically entail moral obligations
  • For example, the fact that an animal can suffer arguably implies a prima facie duty not to cause it unnecessary harm
• Social contract theory grounds moral obligations in the descriptive fact of an agreement between members of society
  • This agreement can be hypothetical or actual
  • However, this may require additional normative premises about the bindingness of agreements
• Attempts to derive ought from is often rely on hidden normative assumptions
  • The gap between facts and values remains difficult to fully bridge

Moral Judgments and Motivation

Internalism: A Necessary Connection

• Moral motivation concerns what role, if any, moral judgments play in motivating moral behavior
  • Do moral beliefs necessarily provide reasons for action?
• Internalism holds there is a necessary or conceptual connection between sincere moral judgments and motivation
  • On this view, to genuinely judge an action as right entails having some motivation to perform that action
• Internalism aligns with the intuition that moral considerations necessarily provide reasons for action
  • It fits the phenomenology of feeling motivated by our moral convictions

Externalism: A Contingent Relationship

• Externalism denies a necessary link between moral judgments and motivation
  • Externalists argue it is psychologically possible to believe an action is right without being motivated to act accordingly
• The Humean theory of motivation states beliefs alone cannot motivate action - motivation requires the presence of a desire
  • If moral judgments are beliefs, external desires would be needed to motivate moral behavior
• Externalism seems to better account for the variability of moral motivation between individuals
  • Moral judgments may only contingently motivate based on a person's desires, attitudes, or sentiments

Internalist vs Externalist Theories

Assessing Internalism

• Internalists argue the connection between moral judgment and motivation is a conceptual truth
  • The very concept of a moral belief involves motivational force
• However, internalism struggles with amoralists - people who seem to make moral judgments without corresponding motivation
  • Internalists may argue such people don't make genuine moral judgments
• Internalism has difficulty explaining cases of weakness of will (akrasia) where we judge an action as right but fail to do it

Assessing Externalism

• Externalists have an easier time explaining amoralism and weakness of will
  • The lack of necessary motivation allows for the psychological possibility of judging an action as right without feeling moved to act
• A challenge for externalism is explaining the strong connection many people feel between their moral beliefs and reasons for action
  • Externalists may argue this connection is merely contingent rather than necessary
• If moral judgments only contingently motivate, it raises questions about the practical relevance and authority of morality
  • Moral considerations may not reliably guide behavior on an externalist account