摘要：It analyses the parameters that a judge must have in mind to take a decision; the judicial decision, when facing concrete facts, pointing out to which extent his freedom goes. The theoretical framework is based on studies on Robert Alexy, from which analysis are made about the collision of rights and the adoption of proportionality to solve this collision of rights. Moreover, the analysis tackles the inclusion of moral in judicial decisions; the search for justice; the use of weighting in judicial decisions, having in mind the relationship between law and moral. To conclude, it analyses the necessity of a law argumentation theory which would allow a coherent judicial decision.
关键词：judicial decision; proportionality; weighs of arguments;Decisão judiciária;Proporcionalidade;Sopesamento de argumentos.
