 The requirement of clarity is also important in this regard. Laws must be public not only in the sense of actual promulgation but also in the sense of accessibility and intelligibly. True, much modern law is necessarily technical (Weber 1968 [1922]: 882–95) and the lay-person will often require professional advice as to what the law requires of him. It is also an important part of the Rule of Law that there be a competent profession available to offer such advice and that the law must be such as to make it possible for professionals at least to get a reliable picture of what the law at any given time requires. In the nineteenth century, Jeremy Bentham (1782: ch. 15 and 1792) criticized customary law in general, and common law in particular, for failing to satisfy this requirement: the sources of law were hidden in obscurity and though there were spurious appeals to precedent, much of the law was just made up by the judges as they went along.