The estoppel put an impediment on its way, Estoppel is thus a shield not a sword; it’s role is defensive not offensive. To use the language of naval warfare, an estoppel must always be either a mine layer or a mine sweeper; it can never be a capital unit. There is nothing like title by estoppel as an estoppel gives no title to that which is the subject matter of the estoppel.
– Nnamani JSC. Gbadamosi v. Bello (1985)