Pure theory of law is a book by legal theorist hans kelsen first published in 1934 and in a greatly expanded second edition in 1960 the second edition appeared in english translation in 1967 as pure theory of law the first edition in english translation in 1992 as introduction to the problems of legal theory the theory proposed in this book has probably been the most influential theory of law produced during the 20th century it is at the least one of the high points of . The pure theory describes the positive law as an objectively valid order and states that this interpretation is possible only under the condition that a basic norm is presupposed the pure theory thereby characterizes this interpretation as possible not necessary and presents the objective validity of positive law only as conditional namely conditioned by the presupposed basic norm pt2 217 218. Pure theory of law is concerned only with that part of knowledge that deals with law and does not include anything which does not belong to law as subject matter and therefore it frees the science of law from the foreign elements according to this theory of law the science of law includes legal norms and does not recognise natural realities. Kelsens pure theory of law with his pure theory of law hans kelsen did not wish to present any new ideology of law rather his aim was to present law as it is free from all the various ideologies he wanted to examine law in its purest form kelsens pure theory can be said to be one of the most refined developments of analytical positivism