Justice, Equality and Tax Law

S. 2601. Nature of a general principle of law

A general principle may be defined as a general proposition of law of some importance from which concrete rules derive. A principle must express a fundamental value and have a minimum degree of recognition by the legal system for it to be accorded the status of a general principle. For instance, the basic premise or core value underlying the principle of equality is that similar and comparable situations should be treated equally. In Mangold, a case brought upon by an employee on the grounds of discrimination based on age, the Court of Justice of the European Union (CJEU) regarded the principle of equal treatment in employment as a general principle of law. It explained that the prohibition of discrimination based on criteria such as age has its source in various international instruments and in the constitutional traditions common to the Member States.

Legal certainty, another well-recognized general principle, requires that a law be clear, easily accessible, comprehensible, prospective rather than retrospective, and relatively stable. Therefore, a provision disallowing business expenses paid to an enterprise of another Member State without ob...