Introduction

One distinguishing feature of equitable remedies is their discretionary nature. Common law remedies accrue as of right once the plaintiff has made out her cause of action. However, equitable relief is not automatic. Equity acts to correct the defendant's conscience and sometimes this may not lead to full recovery, or indeed any recovery, for the plaintiff. Because the court weighs factors from both the plaintiff's and defendant's perspectives ‘that tend towards the justice or injustice of granting the remedy that is sought’, there is some unpredictability involved in equitable remedies.

Nevertheless, it is a mistake to imagine that equitable remedies are entirely unpredictable. When the plaintiff is denied her remedy, or finds her remedy less than she hoped for, or given to her on terms, we are able to point to a set of well-identified grounds that will have informed the court's exercise of discretion. Because these grounds are used to reduce or deny the plaintiff's remedy, they are often referred to as ‘equitable defences’, but they are not defences in the common law sense. They are merely factors relevant to the exercise of remedial discretion. They include the doctrines of laches and acquiescence, unclean hands, and hardship to the defendant. These are by no means the only cases in which equity will deny a plaintiff a remedy. For example, a court exercising equitable jurisdiction will not make an order that is futile, or impossible to supervise. Estoppel, discussed in chapter 7, can operate as a defence. Another highly relevant matter, which is discussed in this chapter, is the effect of the order on third parties.