What is the common law defence of qualified privilege?

The common law practice with regard to a defence of qualified privilege has evolved over many years. In the case of Adam v. Ward, [1917] AC 309, Lord Justice Atkinson described a privileged occasion at para. 21 as follows: It was not disputed in this case on either side that a privileged occasion is, in reference to qualified privilege, an occasion where the person who makes a communication has an interest or a duty, legal, social, or moral, to make it to the person to whom it is made, and the person to whom it is so made has a corresponding interest or duty to receive it. This reciprocity is essential. Nor is it disputed that a privileged communication, a phrase often used loosely to describe a privileged occasion, and vice versa, is a communication made upon an occasion which rebuts the prima facie presumption of malice arising from a statement prejudicial to the character of the plaintiff, and puts the latter on proof that there was malice in fact: