Per Lord Ellenborough in Bilbie v Lumley (1802) 2 East 469 at p.471:
Every man must be taken to be cognizant of the law; otherwise there is no saying to what extent the excuse of ignorance might not be carried. It would be urged in almost every case.
Scruttons Ltd v Midland Silicones Ltd  AC 446 per Viscount Simonds at p.466:
The law is developed by the application of old principles to new circumstances. Therein lies its genius. Its reform by the abrogation of those principles is the task not of the courts of law but of Parliament.