Al ser Derecho y Ley conceptos nucleares del saber jurídico, su determinación no debe restringirse a un mero estudio iuspositivo. Procede un análisis lingüístico que sitúe al estudioso en adecuada atalaya para la posterior reflexión normativa. Es significativo que las dos grandes concepciones presentes en nuestro universo jurídico contemporáneo, common law y civil law, tengan que recurrir al Derecho Romano para explicar su divergente forma de entender y sobre todo de aplicar el Derecho.
Since both Law and Parliamentary Acts are nuclear concepts of the legal knowledge, their definitions should not be restricted to a mere legal study. A linguistic analysis is essential in order proceed with a proper interpretation of Law It is quite significant that both common law and civil law, the two great notions of our legal universe, must make reference to Roman law in an attempt to explain their divergent ways of understanding and applying Law.