22 ‘Although absence of consent is not part of the definition of the crime of [indecent] assault as is the case in rape, the definition as quoted in Gardener & Lansdown includes an averment of “unlawfulness”. The State must, therefore, prove that the act complained of was unlawful . . . Since the act complained in the present case was not malum in se and is only unlawful because of the complainant’s lack of consent, prove of unlawfulness necessarily involved proof of absence of consent. It seems to me therefore that the onus of proving absence of consent rested upon the State.’ (See also S v M 2006 (1) SA 135 (SCA) paras 68 and 284-285; and generally JRL Milton South African Criminal Law and Procedure Vol II Common-law Crimes 3 ed (1996) p 476.) [52] It is therefore clear that, in this case, the onus rested on the State to prove absence of consent by adducing sufficient evidence to negative the reasonable possibility that the complainant consented to the sexual acts in question. From the evidence as a whole, I agree with the regional magistrate and the High Court that the State did not discharge its onus of proof in this regard. [53] Although it may perhaps be unfortunate that, because of the prima facie view expressed by the magistrate early in the trial, the question of consent was not really investigated, this does not affect my conclusion. As was pointed out by Nugent JA in S v M, supra, para 277: ‘The process of examination and cross-examination in a court of law is on occasions a blunt instrument for revealing the truth, and that is particularly so where, as in this case, the evidence concerns matters that might be emotionally and psychologically complex and nuanced. But then it is common for the full truth not to emerge in the course of a criminal trial, which has the limited function of determining whether there is sufficient and adequate evidence to establish beyond reasonable doubt that the accused person committed an offence. In the absence of such proof in relation to each element of the offence the accused person is entitled to be acquitted albeit that the full truth might not have emerged. That applies no matter the nature of the offence.’ Constitutional validity of s 14(1)(b) of Act 23 of 1957 [54] I turn now to deal with the constitutional challenge to s 14(1)(b) of the Act. The relevant provisions of s 14 (headed ‘Sexual offences with youths’), read as follows – (1) Any male person who – (a) has or attempts to have unlawful carnal intercourse with a girl under the age of 16 years; or (b) commits or attempts to commit with such a girl or with a boy under the age of 19 years an immoral or indecent act; or (c) solicits or entices such a girl or boy to the commission of an immoral or indecent act,