Hans Kelsen is one of the most important personalities of jurisprudence. It is questionable whether he can be described as a legal philosopher, because the legal theory presented by him, the pure legal doctrine, should represent a jurisprudence and not a particular legal philosophy.
The pure legal doctrine represents basically a rare approach to the investigation of the legal system, for the reason that it is deliberately value-free. This does not mean that their performers, including Kelsen, would dispute the existence of certain values in law or their presence in the legal systems of individual countries, but this fact was not significant to them.