Not only can the principle be the vehicle by which the law takes account of the particular circumstances of each case, but also interpretation of the principle can be the means by which social change is either adapted to, or else 'engineered' in, a desirable direction. The indeterminacy of the provision also helps to avoid the need to draft unambiguous – but politically contentious – statutory provisions. (Day Sclater & Piper, 2001, p. 412