Law grounded in universal moral principles

Unjust law is not “true” law (fails legitimacy/authority)

Moral standards can invalidate or delegitimize enacted rules

Connection between legality and morality is necessary (stronger versions) or conceptually central (weaker versions)

Thomas Aquinas

John Finnis (New Natural Law)

Lon L. Fuller (procedural natural law)

Law is determined by social facts (sources), not by moral merits

Separation of law and morality (conceptual, not necessarily normative)

Validity depends on pedigree (enactment, recognition, procedure)

A law can be valid yet morally unjust

John Austin (command theory)

H. L. A. Hart

Hans Kelsen (Pure Theory)

Extreme injustice can negate legal validity

“Intolerable” injustice yields no legal character (post-WWII German context)

Whether formally valid but immoral enactments count as “law”

Tension between legal certainty and moral accountability

Hart: validity from social sources; moral critique is separate

Fuller: legality has internal moral requirements; procedural failure undermines “law”

Hart: rules identified by social practices (recognition)

Dworkin: law includes principles, not just rules; adjudication involves moral reasoning (“right answer” in hard cases)

Moral criteria can be part of legal validity if recognized by social rules (e.g., constitutional rights provisions)

Moral considerations never determine validity; only sources do

Law as best moral interpretation of legal practices and institutions

Legality tied to justification, coherence, and political morality

Many systems combine source-based validity with moral-constitutional constraints

Ongoing dispute: whether morality is conceptually necessary to “law” or only contingently embedded by legal practice