Iron law can refer to:

• Iron law of population from Thomas Malthus'
  Thomas Malthus
  The Reverend Thomas Robert Malthus FRS was an English scholar, influential in political economy and demography. Malthus popularized the economic theory of rent....
  
   An Essay on the Principle of Population
  An Essay on the Principle of Population
  The book An Essay on the Principle of Population was first published anonymously in 1798 through J. Johnson . The author was soon identified as The Reverend Thomas Robert Malthus. While it was not the first book on population, it has been acknowledged as the most influential work of its era...
  
  (1798)
• Iron law of wages from Ferdinand Lassalle's
  Ferdinand Lassalle
  Ferdinand Lassalle was a German-Jewish jurist and socialist political activist.-Early life:Ferdinand Lassalle was born on 11 April 1825 in Breslau , Silesia to a prosperous Jewish family descending from Upper Silesian Loslau...
  
   Subsistence theory of wages
  Subsistence theory of wages
  The iron law of wages is a proposed law of economics that asserts that real wages always tend, in the long run, toward the minimum wage necessary to sustain the life of the worker. The theory was first named by Ferdinand Lassalle in the mid-nineteenth century...
  
  (mid 19th century)
• Iron law of oligarchy
  Iron law of oligarchy
  The iron law of oligarchy is a political theory, first developed by the German syndicalist sociologist Robert Michels in his 1911 book, Political Parties. It states that all forms of organization, regardless of how democratic they may be at the start, will eventually and inevitably develop into...
  
   from Michels' Political Parties
• Iron law of prohibition
  Iron law of prohibition
  The iron law of prohibition is a term coined by Richard Cowan which states that "the more intense the law enforcement, the more potent the prohibited substance becomes." This is based on the premise that when drugs or alcohol are prohibited, they will be produced only in black markets in their most...
  
   from Cohen's How the Narcs Created Crack
• Jerry Pournelle's Iron Law of Bureaucracy
  Jerry Pournelle
  Jerry Eugene Pournelle is an American science fiction writer, essayist and journalist who contributed for many years to the computer magazine Byte and has since 1998 been maintaining his own website/blog....
  
  
• Iron law of institutions

The term is derived from Goethe's "great, eternal iron laws" in his poem Das Göttliche, (On The Divine), from Ilmenau

Ilmenau

Ilmenau is a town located in the district of Ilm-Kreis, Thuringia, Germany.Ilmenau is situated in the valley of the Ilm river, at an altitude of 431 metres above sea level, and is the biggest town in Ilm-Kreis district, with 6,200 students studying at the Technische Universität Ilmenau. The...

(1783) (» Nach ewigen, ehrnen, / Großen Gesetzen «; word for word "by eternal, iron, / great laws", lines 31–32, sixth stanza; for ehrnen, (iron/firm/unyielding) compare ehernen, ehern,) which was applied by Lassalle in economics. Malthus' principle was then retrospectively retitled an "iron law", and subsequent such laws have been named in imitation of these.