This paper reviews recent developments in the controversial areas of breach of warranty and good faith in insurance contracts, in particular the mutuality of the obligation of good faith and the post-contractual duty of good faith. It calls for reform as part of a general statutory overhaul of insurance law .

It is a great privilege to be asked to give the 21st Donald O’May lecture, which seems to have come of age remarkably quickly. My sense of privilege is partly due to the distinguished line of lecturers of which I now find myself the latest and least conspicuous member. Anyone who had the good fortune of being present at Lord Justice Rix’s lecture last year will remember what a tour de force of a comparatively unusual area of the law it was. I can say that without fear of contradiction, since he has told me in advance that he is not going to be in the audience. My main reason, however, for feeling it is a privilege to be here is because I knew Donald O’May a little and, like all who knew him, was much in awe of his reputation both as solicitor and author. His contributions to the law of marine insurance have stood the test of time and remind one of not only his magisterial authority but also the twinkle in his eye, although I do have to announce, in a very small voice and with the utmost regret, that I have found one error in his seminal book. This twinkle in the eye extended to his prose; no doubt many a writer on insurance could have been diligent enough to unearth the comment of an American judge in 19541 in relation to the old S.G. Form, in use for 200 years, that it was, like a woman, ‘‘fearfully, wondrously wrought’’. Only Donald could have added by way of footnote that this was said ‘‘more in awe of its intriguing subtleties, rather than in admiration of its shapely form’’.2