It is argued that accepting that there are human rights, or that there are categorically binding requirements of any kind on action, logically requires accepting the PGC (Principle of Generic Consistency) as the supreme criterion of practical reasonableness.Consequently, all legal systems that recognise human rights (hence, the English legal system), all who view law as a matter of obligation, and all who consider that there are categorically binding requirements on action, must take the PGC to be a necessary criterion of (...) legal validity. Conventions on human rights must, as conventions on human rights, be interpreted to conform with the PGC. (shrink)