What are the principles of amending a pleading?

Matthews J.A. discussed the principles of amending pleadings in White v. Pellerine (1988), 84 N.S.R. (2d) 341 (S.C.A.D.), where the appellants sought an amendment after trial but before the decision. At p. 342 he wrote: It is clear from the case law that such an amendment should be allowed if it can be made without injustice to the other party and further that there is no injustice if that other party can be compensated with costs.... It is our opinion that if the amendment be allowed the parties would be in the same position for the purposes of justice that they were in when the plea of negligence now sought was not alleged. Although a new cause of action will be created, it arises out of the same facts as the cause of action already asserted.... While we cannot condone the fact that the appellants’ solicitor failed to request the amendment much earlier, we are of the opinion that the parties here would not have conducted the proceeding in any manner different than was done to date, nor is it now necessary for either party to adduce further evidence. Granting the amendment will only entail the submission of further briefs. This does not create an injustice.