Contents. Introduction : Five conceptions of rationality.-- Talking with a tradition. 1. Contexts.-- 2. Texts.-- 3. Pretexts.-- Historical essays. 4. Adequacy and the individuation of ideas in Spinoza´s ethics.-- 5. Leibniz and degrees of perception.-- 6. Holism and idealism in Hegel´s phenomenology.-- 7. Some pragmatist themes in Hegel´s idealism.-- 8. Frege´s technical concepts.-- 9. The significance of complex numbers for frege´s philosophy mathematics.-- 10. Heidegger´s categories in sein und zeit.-- 11. Dasein, the being that thematizes.-- 12. The centrality of sellars´s two-ply account of observation to the arguments of "empiricism and the philosophy of mind". Incluye notas de página e índices