'I confess that I have found some difficulty—or should find some difficulty if it were necessary to make up my mind and express a view whether all five requisites which Fry, J., stated in the case of Willmott v. Barber, 15 Ch.D 96 must be present in every case in which it is said that the plaintiff will be deprived of his right to succeed in an action on the ground of acquiescence. All cases (and this is a trite but useful observation to repeat) must be read in the light of the facts of the particular cases.'
“Furthermore the more recent cases indicate, in my judgment, that the application of the Ramsden v Dyson LR 1 HL 129 principle — whether you call it proprietary estoppel, estoppel by acquiescence or estoppel by encouragement is really immaterial — requires a very much broader approach which is directed rather at ascertaining whether, in particular individual circumstances, it would be unconscionable for a party to be permitted to deny that which, knowingly, or unknowingly, he has allowed or encouraged another to assume to his detriment than to inquiring whether the circumstances can be fitted within the confines of some preconceived formula serving as a universal yardstick for every form of unconscionable behaviour.”