Editing Irreducible complexity (section)

== Definitions ==
[[Michael Behe]] defined irreducible complexity in natural selection in terms of well-matched parts in his 1996 book ''[[Darwin's Black Box]]'':
<blockquote>... a single system composed of several well-matched, interacting parts that contribute to the basic function, wherein the removal of any one of the parts causes the system to effectively cease functioning.<ref name="Behe 1996 p. 39" /></blockquote>

A second definition given by Behe in 2000 (his "evolutionary definition") states:
<blockquote>An irreducibly complex evolutionary pathway is one that contains one or more unselected steps (that is, one or more necessary-but-unselected mutations). The degree of irreducible complexity is the number of unselected steps in the pathway.<ref>''In Defense of the Irreducibility of the Blood Clotting Cascade: Response to Russell Doolittle, Ken Miller and Keith Robison'', July 31, 2000, [http://www.discovery.org/a/442 Discovery Institute article] {{Webarchive|url=https://web.archive.org/web/20150906193225/http://www.discovery.org/a/442 |date=2015-09-06 }}</ref></blockquote>

Intelligent-design advocate [[William A. Dembski]] assumed an "original function" in his 2002 definition:
<blockquote>A system performing a given basic function is irreducibly complex if it includes a set of well-matched, mutually interacting, nonarbitrarily individuated parts such that each part in the set is indispensable to maintaining the system's basic, and therefore original, function. The set of these indispensable parts is known as the irreducible core of the system.<ref>{{cite book
 | last1 = Dembski
 | first1 = William A.
 | author-link1 = William A. Dembski
 | year = 2002
 | title = No Free Lunch: Why Specified Complexity Cannot Be Purchased Without Intelligence
 | url = https://books.google.com/books?id=qCDp8MjkkLQC
 | location = Lanham, Maryland
 | publisher = Rowman & Littlefield
 | publication-date = 2006
 | page = 285
 | isbn = 978-0-7425-5810-6
 | access-date = 1 November 2020
 | quote = A system performing a given basic function is ''irreducibly complex'' if it includes a set of well-matched, mutually interacting, nonarbitrarily individuated parts such that each part in the set is indispensable to maintaining the system's basic, and therefore original, function. The set of these indispensable parts is known as the ''irreducible core'' of the system.
}}</ref>

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