Principles, Rules, D v S, Dworkin v Positivism

Rules

·       Apply in an all-or-nothing fashion.

·       If two rules conflict (one is invalid)

Principles

·       Provide reasons with weight, not strict conditions.

·       More moral in content: they justify rules & outcomes.

·       Conflict is resolved by deciding which principle has greater weight.

This distinction is central to Ronald Dworkin’s critique of Hartian positivism.

Why principles Matter (Dworkin’s Argument)

·       Dworkin claims positivism is incomplete because it describes law as a system of rules, but courts regularly rely on principles that:

o   Are not enacted.

o   Are not authoritative in the positivist sense.

o   Do not have clear pedigree.

o   Still function as binding reasons in legal argument.

·       Example:

o   In Riggs v Palmer, the court applied a principle (no man should profit from his own wrong) despite contrary statute.

Donoghue v Stevenson 1932

Central Case for principle in judicial reasoning

·       The House of lords created the neighbour principle:

‘You owe a duty of care to those reasonably and foreseeably affected by your

Why does D v S 1932 matter?

·       No such general duty existed previously.

·       Prior case law was narrower & category-based.

·       Judges appeared to be articulating a new general principle, not simply applying established rules.

Why is D v S 1932 a key battleground?

·       Hart – judges created new law in penumbra cases.

·       Dworkin – judges discover the principle that best fits & justified existing law.

Dworkin’s Theory of law as integrity

a)     Judges interpret law using principles to present the legal system as a coherent whole.

·       Interpretation aims at ‘fit’ & ‘justification’

·       Not merely predicting what judges do, but what they ought to decide.

b)     Hard cases do not involve judicial discretion

·       There is a right answer determined by the moral reading of law.

c)     Principles constrain judges

·       Judicial reasoning is not legislative, it is interpretive.

Hart’s Positivist response

Hart accepts that some cases fall into a penumbra where:

·       Rules run out,

·       Language is vague,

·       Judges must exercise limited legislative discretion.

Hart denies that principles are ‘binding law’ unless:

·       They have been incorporated via the rule of recognition.

Thus, for Hart:

·       Judges do create law in hard cases.

·       This law creation is an unavoidable feature of open-texture language.

Did the judges in Donoghue make law? (Positivist View)

·       Yes, the neighbour principle did not exists before.

·       The court extended negligence radically – judicial legislation.

Did the judges in Donoghue make law?

·       No, judges justified the moral principle underlying existing precedents:

o   Justice,

o   Reasonableness,

o   Foreseeability.

·       Thus, Donoghue = uncovering deeper coherence, NOT legislating.

Why does this debate matter for legal theory?

·       Shows the limits of rule-based explanations of law.

·       Introduces law’s moral dimension via principles.

·       Challenges positivism’s separation of law and morality.

·       Highlights judicial creativity and legitimacy under the rule of law.

Conclusion:

Dworkin’s use of principles, exemplified in Donoghue v Stevenson, challenges Hart’s positivist conception of law as rule-based and morally neutral. For Dworkin, principles are fundamental to legal reasoning and constrain judicial decisions even in hard cases. Hart, rejecting this, argues that judges inevitably legislate when rules run out. The disagreement reflects two views of legality: law as conventional social fact, or law as a morally interpretive enterprise.