“The importance of pleadings cannot be overemphasized. They define the issues in dispute. They give notice to the other side of the case to be met. They inform the court of the matters in issue. They provide a permanent record of the issues raised in deciding the action so as to prevent further litigation upon the same matters already judicially determined. They also play a key role in defining the scope of discovery.”
— Aristocrat Restaurants Ltd. v. Ontario,  O.J. No. 5331, 2003 CarswellOnt 5574 (Ont. Sup. Ct.) at para. 15, per Epstein J. (now J.A.).