Law
Law is a system of rules that are created and enforced through social or governmental institutions to regulate behavior. Law is a system that regulates and ensures that individuals or a community adhere to the will of the state. State-enforced laws can be made by a collective legislature or by a single legislator, resulting in statutes, by the executive through decrees and regulations, or established by judges through precedent, normally in common law jurisdictions. Private individuals can create legally binding contracts, including arbitration agreements that may elect to accept alternative arbitration to the normal court process. The formation of laws themselves may be influenced by a constitution, written or tacit, and the rights encoded therein. The law shapes politics, economics, history and society in various ways and serves as a mediator of relations between people.
Theory
A theory is a contemplative and rational type of abstract or generalizing thinking, or the results of such thinking. Depending on the context, the results might, for example, include generalized explanations of how nature works. The word has its roots in ancient Greek, but in modern use it has taken on several related meanings.
State
The state is a means to an end. Its end lies in the preservation and advancement of a community of physically and psychically homogeneous creatures. This preservation itself comprises first of all existence as a race and thereby permits the free development of all the forces dormant in this race. Of them a part will always primarily serve the preservation of physical life, and only the remaining part the promotion of a further spiritual development. Actually the one always creates the precondition for the other. States which do not serve this purpose are misbegotten, monstrosities in fact. The fact of their existence changes this no more than the success of a gang of bandits can justify robbery
Adolf Hitler, Mein Kampf (1925), Chapter 2: the State