In the light of common law, there are two types of law: natural law which emphasise on the moral side that emphasise on Biblical, utilitarianism and Kantian philosophy and positive law which are man-made laws. The different sources of positive law: legislatures, precedents, treaties, convention and European directives (effective until the formal exit of the UK from the EU).
If these set of rules that govern the human society then by virtue we would be a society that could have been extinct or it shows that our civilisation has not evolved. Do rules signify our present day human evolution? In a sense it does! Legislations are often a result of social change and social attitude for example pre-World War II homosexuality is illegal whereas today same-sex marriages and civil unions are now recognised in legal in some places. A change of social attitude is shows the progress and development of a society. The limitations of natural law arose to positive law – setting aside rules and regulations. Utilitarian flaw is that when a carnivore is hungry, one must eat meat which of course results to cannibalism or killing an animal – if there isn't any legislation against cannibalism, the human race could either be living zombie-like creatures and may lead humans to vulnerable species. Kantian philosophy in the light of his view on morality ('Critique of Pure Reason') one must obey a certain rule. For example if the rule is 'one hundred per cent honesty' then if you see a killer chasing another person and then killer asks you which direction did the person he is chasing ran to then as the rule says honesty you will tell the truth thus killing the person. However, the Kantian philosophy may be helpful in the development of warfare law. Nonetheless, in private laws such as in criminal – then not sparing the other person's life may satisfy the law on abetting acting as an accessory of the crime regardless whether it is a police chasing a suspect.
There is no such thing as perfect laws and that is the beauty of social development and changes in attitude in our human society. The flexibility of common law means that precedents can often make up for a stringent justice statute or a precedent can give more justice in the absence of a more justifiable statute. A 'civilisation' without laws is impossible. Even wild animals have set of rules such as for canines it is the pack leader that directs the rules as for felines it is the Lion of the pride. Without a leader whether bad or good we would all is running like headless chickens striving to get power. Even 'bad' or unacceptable leadership often bring good. First, it increases the awareness of private citizens. Second, it often brings creativity – the peculiarities of Russian art in which artists must only depict happiness and wealth arose to the prominence of Wassily Kandinsky, a famous Dadaist.