What is the test for the equitable doctrine of undue influence?

The trial judge referred to the relevant legal principles in Geffen v. Goodman Estate, 1991 CanLII 69 (SCC), [1991] 2 S.C.R. 353, noting that the equitable doctrine of undue influence was developed not to save people from the consequences of their own folly but to save them from being victimized by other people. She also observed that, while it is natural to presume that influence will exist in a relationship in which trust and confidence is reposed in the donee by the donor, the factual underpinning of the process leading up to the gift must be examined in the context of equity protecting the “weak or momentarily weak, not from bad bargains, but from the abuse of trust, confidence or power”.