Basic norm (German: Grundnorm) is a concept in the Pure Theory of Law created by Hans Kelsen, a jurist and legal philosopher. Kelsen used this word to denote the basic norm, order, or rule that forms an underlying basis for a legal system. The theory is based on a need to find a point of origin for all law, on which basic law and the constitution can gain their legitimacy (akin to the concept of first principles). This "basic norm", however, is often described as hypothetical. The reception of the term has fallen into three broad areas of discernment including (i) Kelsen's original introduction of the term, (ii) the Neo-Kantian reception of the term by Kelsen's critics and followers, and (iii) the hypothetical and symbolic use of the term through the history of its application.