Henry John Temple, 3rd Viscount Palmerston, Lord Palmerston to the Minister of the Emperor of China (1840)
“ Now if a Government makes a Law which applies both to its own Subjects and to Foreigners, such Government ought to enforce that Law impartially or not at all. If it enforces that Law on Foreigners, it is bound to enforce it also upon its own Subjects; and it has no right to permit its own Subjects to violate the Law with impunity, and then to punish Foreigners for doing the very same thing. ”
