Filosofia do Direito
Core concepts
Positivism: Austin (command), Kelsen (basic norm, validity and efficacy), Hart (rule of recognition, open texture, inclusive positivism). Natural law: a higher order above positive law. Post-positivism: principles as norms (Dworkin, rules versus principles), proportionality and balancing (Alexy and the weight formula). Hermeneutics (Gadamer and the fusion of horizons), argumentation (Perelman and the universal audience; Habermas and communicative action) and justice (Rawls: original position, veil of ignorance, difference principle). Critical approaches: Marx, Foucault and Schmitt.
Traps
Questions mix exclusive positivism (Raz) with inclusive positivism (Hart). Dworkin is not a natural lawyer, though he criticises positivism. Balancing is not arbitrary: it requires adequacy, necessity and proportionality in the strict sense.
Rule of thumb
Ask whether the author treats principles as binding norms. If yes, you are in post-positivism. Worked example: a decision that resolves a collision of rights through the weight formula follows Alexy.