The facts to be proven in a lawsuit can be more or less probable. But the recognition of the relevant facts may require discretion or evaluative operations; moreover, a just and equitable interpretation of a contract may depend on what the contracting parties knew about the intentions of each other. Can, e.g., negligence be more or less probable? Can Ought be proven? There is, however, a structural similarity between legal interpretation and the evalution of evidence and not only an intertwinement (...) between the so-called questions of fact and the questions of law. A number of situations is briefly analysed: the interpretation of contracts, the interest of the child, the basic concepts of the law of torts and the criminal intent. (shrink)