The basic conditions for the development of modern administrative sciences arose with the emergence of the constitutional state with its guarantees of respect for the rights of the individual, the functional and organizational division of public authorities and the mechanisms for controlling the legality of the functioning of the state apparatus. The concept of the constitutional state was derived directly from the ideology of the Enlightenment, based on the social contract theory, the doctrine of the law of nature and the theory of the division and control of public authorities. It was implemented at the earliest in revolutionary France, and during the nineteenth century it was embraced by all – except Russia – European countries, which by the end of this century adopted the construct of a constitutional state of law.