O’REGAN J and SACHS J [57] The appellants argued that to the extent that section 20(1)(aA) criminalises only the conduct of the prostitutes and not that of the client, it is in breach of section 8 of the Constitution. The proper approach to section 8 of the interim Constitution was confirmed and summarised in Harksen v Lane NO and Others.20 There are two enquiries: the first is to consider whether the impugned provision differentiates between people or categories of people and if it does, whether it does so rationally. The second is to consider whether a differentiation is made, directly or indirectly on a ground which could be said to have the potential to impair human dignity or to affect people adversely in a comparably serious manner. If the differentiation is on such a ground, the question that then arises is whether it is unfair or not. [58] The differentiation in this case is between prostitutes and patrons. The conduct of one group is rendered criminal by the section, that of the other, not.21 It cannot be said that it is irrational for the Legislature to criminalise the conduct of only one group and not the other. The legislative purpose may be to target the purveyors of sex for reward, rather than the purchasers. In each case the question at this stage is the narrow one of whether it is rational for the law to punish only one side of the bargain. In our view, in this case it cannot be said that rendering criminal the conduct of the prostitute and not that of the client is so lacking in any plausible foundation as to be irrational. 20 1998 (1) SA 300 (CC) at para 54; 1997 (11) BCLR 1489 (CC) at para 53. 21 We are not dealing here with the question of accomplice or accessory liability, something we consider below at paras 60ff. 34