Facts and values, truth and values. These are the terms that are the premise of this analysis. The aim is to ask oneself about Law and its foundation. In particular, two different questions require a new and more updated discussion: one is dedicated mainly to what the Law prescribes in a certain place and at a certain time (quid iuris) (Science of Law), and the other, instead, concerns above all justice (quid ius) (Philosophy of Law). It is only from the tension between Law and Justice that the jurist can be reconciled with jurisprudence and fulfill what – in hindsight – is his fundamental task: setting checks and balances to legislation for the protection of human rights.