Limitations - Generally. Canadian Imperial Bank of Commerce v. Green
In Canadian Imperial Bank of Commerce v. Green (SCC, 2015) the Supreme Court of Canada considered basic principles underpinning the existence of limitation periods:
 This Court has generally recognized that limitation periods have three purposes known as the certainty, evidentiary and diligence rationales: Novak v. Bond, 1999 CanLII 685 (SCC),  1 S.C.R. 808, at paras. 64-67, per McLachlin J.; M. (K.) v. M. (H.), 1992 CanLII 31 (SCC),  3 S.C.R. 6, at pp. 29-31, per La Forest J. Limitation periods serve “(1) to promote accuracy and certainty in the adjudication of claims; (2) to provide fairness to persons who might be required to defend against claims based on stale evidence; and (3) to prompt persons who might wish to commence claims to be diligent in pursuing them in a timely fashion”: P. M. Perell and J. W. Morden, The Law of Civil Procedure in Ontario (2nd ed. 2014), at p. 123.
 Clearly, it is desirable that litigation be accurate and certain, given that the passage of time dims memories and erodes evidence, and also that the risk of error grows as an adjudicator is further removed from the cause of action. Furthermore, after a certain time, possible defendants may be unaware of the need to preserve potentially enlightening or even exonerating pieces of evidence. Finally, it is appropriate to expect plaintiffs to assert their claims diligently and to be cognizant of their circumstances and of the extent of their control over them. Modern limitations legislation is therefore based on a recognition that limitation periods, in order to be effective, need to be final. This is the other side of the coin, the practical consequence of limitation periods that can make the application of a limitations statute seem harsh: Novak, at para. 8, per Iacobucci and Major JJ, dissenting.