CINXE.COM
Archives of the Stanford Encyclopedia of Philosophy
<!DOCTYPE html> <!--[if lt IE 7]> <html class="ie6 ie"> <![endif]--> <!--[if IE 7]> <html class="ie7 ie"> <![endif]--> <!--[if IE 8]> <html class="ie8 ie"> <![endif]--> <!--[if IE 9]> <html class="ie9 ie"> <![endif]--> <!--[if !IE]> --> <html lang="en"> <!-- <![endif]--> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <title>Archives of the Stanford Encyclopedia of Philosophy</title> <!-- NOTE: Import webfonts using this link: --> <link href="https://fonts.googleapis.com/css?family=Source+Sans+Pro:400,300,600,200&subset=latin,latin-ext" rel="stylesheet" type="text/css" /> <link rel="stylesheet" type="text/css" media="screen" href="../css/bootstrap.min.css" /> <link rel="stylesheet" type="text/css" media="screen" href="../css/bootstrap-responsive.min.css" /> <link rel="stylesheet" type="text/css" href="../css/font-awesome.min.css" /> <!--[if IE 7]> <link rel="stylesheet" type="text/css" href="../css/font-awesome-ie7.min.css"> <![endif]--> <link rel="stylesheet" type="text/css" media="screen" href="../css/style.css" /> <link rel="stylesheet" type="text/css" media="print" href="../css/print.css" /> <link rel="stylesheet" type="text/css" href="../css/entry.css" /> <!--[if IE]> <link rel="stylesheet" type="text/css" href="../css/ie.css" /> <![endif]--> <script type="text/javascript" src="../js/jquery-1.9.1.min.js"></script> <script type="text/javascript" src="../js/bootstrap.min.js"></script> <!-- SEP custom script --> <script type="text/javascript" src="../js/sep.js"></script> </head> <!-- NOTE: The nojs class is removed from the page if javascript is enabled. Otherwise, it drives the display when there is no javascript. --> <body class="nojs" id="pagetopright"> <div id="container"> <div id="header-wrapper"> <div id="header"> <div id="branding"> <div id="site-logo"><a href="../index.html"><img src="../symbols/sep-man-red.png" alt="SEP logo" /></a></div> <div id="site-title"><a href="../index.html">Stanford Encyclopedia of Philosophy</a></div> </div> <div id="navigation"> <div class="navbar"> <div class="navbar-inner"> <div class="container"> <button class="btn btn-navbar collapsed" data-target=".nav-collapse" data-toggle="collapse" type="button"> <i class="icon-reorder"></i> Menu </button> <div class="nav-collapse in collapse"> <ul class="nav"> <li class="dropdown open"><a id="drop1" href="#" class="dropdown-toggle" data-toggle="dropdown" role="button"><i class="icon-book"></i> Browse</a> <ul class="dropdown-menu" role="menu" aria-labelledby="drop1"> <li role="menuitem"><a href="../contents.html">Table of Contents</a></li> <li role="menuitem"><a href="../new.html">What's New</a></li> <li role="menuitem"><a href="https://plato.stanford.edu/cgi-bin/encyclopedia/random">Random Entry</a></li> <li role="menuitem"><a href="../published.html">Chronological</a></li> <li role="menuitem"><a href="../archives/">Archives</a></li> </ul> </li> <li class="dropdown open"><a id="drop2" href="#" class="dropdown-toggle" data-toggle="dropdown" role="button"><i class="icon-info-sign"></i> About</a> <ul class="dropdown-menu" role="menu" aria-labelledby="drop2"> <li role="menuitem"><a href="../info.html">Editorial Information</a></li> <li role="menuitem"><a href="../about.html">About the SEP</a></li> <li role="menuitem"><a href="../board.html">Editorial Board</a></li> <li role="menuitem"><a href="../cite.html">How to Cite the SEP</a></li> <li role="menuitem"><a href="../special-characters.html">Special Characters</a></li> <li role="menuitem"><a href="../tools/">Advanced Tools</a></li> <li role="menuitem"><a href="../contact.html">Contact</a></li> </ul> </li> <li class="dropdown open"><a id="drop3" href="#" class="dropdown-toggle" data-toggle="dropdown" role="button"><i class="icon-leaf"></i> Support SEP</a> <ul class="dropdown-menu" role="menu" aria-labelledby="drop3"> <li role="menuitem"><a href="../support/">Support the SEP</a></li> <li role="menuitem"><a href="../support/friends.html">PDFs for SEP Friends</a></li> <li role="menuitem"><a href="../support/donate.html">Make a Donation</a></li> <li role="menuitem"><a href="../support/sepia.html">SEPIA for Libraries</a></li> </ul> </li> </ul> </div> </div> </div> </div> </div> <!-- End navigation --> <div id="search"> <form id="search-form" method="get" action="../search/searcher.py"> <input type="search" name="query" placeholder="Search SEP" /> <div class="search-btn-wrapper"><button class="btn search-btn" type="submit" aria-label="search"><i class="icon-search"></i></button></div> </form> <!-- <a class="advanced-search" href="../search/searcher.py">Advanced Search</a> --> </div> <!-- End search --> </div> <!-- End header --> </div><!-- End header wrapper --> <div id="content"><!--DO NOT MODIFY THIS LINE AND ABOVE--> <h1>Archives of the Stanford Encyclopedia of Philosophy</h1> <div class="notice"> <strong>Notice:</strong> These archives contain periodically fixed editions of the Encyclopedia which may be used for purposes of citation. The content of these editions is neither updated nor modified in any way once the archive is made. The external links (to places on the World Wide Web) and author email addresses contained in the entries of these editions may no longer be functional! Also, you can search the entire archives only at the main Stanford website; you can search only the last 8–10 years of archives at the mirror sites. </div> <p></p> <div align="center"> <a href="../search/searcher.py?archive=entire"><strong>Search The Archives</strong></a> <br /> <a href="../cite.html"><strong>How to Cite This Encyclopedia</strong></a> </div> <h3>The Fixed Editions:</h3> <a href="fall2024/">Fall 2024 Edition</a> (September 21, 2024) <br /> <a href="sum2024/">Summer 2024 Edition</a> (June 21, 2024) <br /> <a href="spr2024/">Spring 2024 Edition</a> (March 21, 2024) <br /> <a href="win2023/">Winter 2023 Edition</a> (December 21, 2023) <br /> <a href="fall2023/">Fall 2023 Edition</a> (September 21, 2023) <br /> <a href="sum2023/">Summer 2023 Edition</a> (June 21, 2023) <br /> <a href="spr2023/">Spring 2023 Edition</a> (March 21, 2023) <br /> <a href="win2022/">Winter 2022 Edition</a> (December 21, 2022) <br /> <a href="fall2022/">Fall 2022 Edition</a> (September 21, 2022) <br /> <a href="sum2022/">Summer 2022 Edition</a> (June 21, 2022) <br /> <a href="spr2022/">Spring 2022 Edition</a> (March 21, 2022) <br /> <a href="win2021/">Winter 2021 Edition</a> (December 21, 2021) <br /> <a href="fall2021/">Fall 2021 Edition</a> (September 21, 2021) <br /> <a href="sum2021/">Summer 2021 Edition</a> (June 21, 2021) <br /> <a href="spr2021/">Spring 2021 Edition</a> (March 21, 2021) <br /> <a href="win2020/">Winter 2020 Edition</a> (December 21, 2020) <br /> <a href="fall2020/">Fall 2020 Edition</a> (September 21, 2020) <br /> <a href="sum2020/">Summer 2020 Edition</a> (June 21, 2020) <br /> <a href="spr2020/">Spring 2020 Edition</a> (March 21, 2020) <br /> <a href="win2019/">Winter 2019 Edition</a> (December 21, 2019) <br /> <a href="fall2019/">Fall 2019 Edition</a> (September 21, 2019) <br /> <a href="sum2019/">Summer 2019 Edition</a> (June 21, 2019) <br /> <a href="spr2019/">Spring 2019 Edition</a> (March 21, 2019) <br /> <a href="win2018/">Winter 2018 Edition</a> (December 21, 2018) <br /> <a href="fall2018/">Fall 2018 Edition</a> (September 21, 2018) <br /> <a href="sum2018/">Summer 2018 Edition</a> (June 21, 2018) <br /> <a href="spr2018/">Spring 2018 Edition</a> (March 21, 2018) <br /> <a href="win2017/">Winter 2017 Edition</a> (December 21, 2017) <br /> <a href="fall2017/">Fall 2017 Edition</a> (September 21, 2017) <br /> <a href="sum2017/">Summer 2017 Edition</a> (June 21, 2017) <br /> <a href="spr2017/">Spring 2017 Edition</a> (March 21, 2017) <br /> <a href="win2016/">Winter 2016 Edition</a> (December 21, 2016) <br /> <a href="fall2016/">Fall 2016 Edition</a> (September 21, 2016) <br /> <a href="sum2016/">Summer 2016 Edition</a> (June 21, 2016) <br /> <a href="spr2016/">Spring 2016 Edition</a> (March 21, 2016) <br /> <a href="win2015/">Winter 2015 Edition</a> (December 21, 2015) <br /> <a href="fall2015/">Fall 2015 Edition</a> (September 21, 2015) <br /> <a href="sum2015/">Summer 2015 Edition</a> (June 21, 2015) <br /> <a href="spr2015/">Spring 2015 Edition</a> (March 21, 2015) <br /> <a href="win2014/">Winter 2014 Edition</a> (December 21, 2014) <br /> <a href="fall2014/">Fall 2014 Edition</a> (September 21, 2014) <br /> <a href="sum2014/">Summer 2014 Edition</a> (June 21, 2014) <br /> <a href="spr2014/">Spring 2014 Edition</a> (March 21, 2014) <br /> <a href="win2013/">Winter 2013 Edition</a> (December 21, 2013) <br /> <a href="fall2013/">Fall 2013 Edition</a> (September 21, 2013) <br /> <a href="sum2013/">Summer 2013 Edition</a> (June 21, 2013) <br /> <a href="spr2013/">Spring 2013 Edition</a> (March 21, 2013) <br /> <a href="win2012/">Winter 2012 Edition</a> (December 21, 2012) <br /> <a href="fall2012/">Fall 2012 Edition</a> (September 21, 2012) <br /> <a href="sum2012/">Summer 2012 Edition</a> (June 21, 2012) <br /> <a href="spr2012/">Spring 2012 Edition</a> (March 21, 2012) <br /> <a href="win2011/">Winter 2011 Edition</a> (December 21, 2011) <br /> <a href="fall2011/">Fall 2011 Edition</a> (September 21, 2011) <br /> <a href="sum2011/">Summer 2011 Edition</a> (June 21, 2011) <br /> <a href="spr2011/">Spring 2011 Edition</a> (March 21, 2011) <br /> <a href="win2010/">Winter 2010 Edition</a> (December 21, 2010) <br /> <a href="fall2010/">Fall 2010 Edition</a> (September 21, 2010) <br /> <a href="sum2010/">Summer 2010 Edition</a> (June 21, 2010) <br /> <a href="spr2010/">Spring 2010 Edition</a> (March 21, 2010) <br /> <a href="win2009/">Winter 2009 Edition</a> (December 21, 2009) <br /> <a href="fall2009/">Fall 2009 Edition</a> (September 21, 2009) <br /> <a href="sum2009/">Summer 2009 Edition</a> (June 21, 2009) <br /> <a href="spr2009/">Spring 2009 Edition</a> (March 21, 2009) <br /> <a href="win2008/">Winter 2008 Edition</a> (December 21, 2008) <br /> <a href="fall2008/">Fall 2008 Edition</a> (September 21, 2008) <br /> <a href="sum2008/">Summer 2008 Edition</a> (June 21, 2008) <br /> <a href="spr2008/">Spring 2008 Edition</a> (March 21, 2008) <br /> <a href="win2007/">Winter 2007 Edition</a> (December 21, 2007) <br /> <a href="fall2007/">Fall 2007 Edition</a> (September 21, 2007) <br /> <a href="sum2007/">Summer 2007 Edition</a> (June 21, 2007) <br /> <a href="spr2007/">Spring 2007 Edition</a> (March 21, 2007) <br /> <a href="win2006/">Winter 2006 Edition</a> (December 21, 2006) <br /> <a href="fall2006/">Fall 2006 Edition</a> (September 21, 2006) <br /> <a href="sum2006/">Summer 2006 Edition</a> (June 21, 2006) <br /> <a href="spr2006/">Spring 2006 Edition</a> (March 21, 2006) <br /> <a href="win2005/">Winter 2005 Edition</a> (December 21, 2005) <br /> <a href="fall2005/">Fall 2005 Edition</a> (September 21, 2005) <br /> <a href="sum2005/">Summer 2005 Edition</a> (June 21, 2005) <br /> <a href="spr2005/">Spring 2005 Edition</a> (March 21, 2005) <br /> <a href="win2004/">Winter 2004 Edition</a> (December 21, 2004) <br /> <a href="fall2004/">Fall 2004 Edition</a> (September 21, 2004) <br /> <a href="sum2004/">Summer 2004 Edition</a> (June 21, 2004) <br /> <a href="spr2004/">Spring 2004 Edition</a> (March 21, 2004) <br /> <a href="win2003/">Winter 2003 Edition</a> (December 21, 2003) <br /> <a href="fall2003/">Fall 2003 Edition</a> (September 21, 2003) <br /> <a href="sum2003/">Summer 2003 Edition</a> (June 21, 2003) <br /> <a href="spr2003/">Spring 2003 Edition</a> (March 21, 2003) <br /> <a href="win2002/">Winter 2002 Edition</a> (December 21, 2002) <br /> <a href="fall2002/">Fall 2002 Edition</a> (September 21, 2002) <br /> <a href="sum2002/">Summer 2002 Edition</a> (June 21, 2002) <br /> <a href="spr2002/">Spring 2002 Edition</a> (March 21, 2002) <br /> <a href="win2001/">Winter 2001 Edition</a> (December 21, 2001) <br /> <a href="fall2001/">Fall 2001 Edition</a> (September 21, 2001) <br /> <a href="sum2001/">Summer 2001 Edition</a> (June 21, 2001) <br /> <a href="spr2001/">Spring 2001 Edition</a> (March 21, 2000) <br /> <a href="win2000/">Winter 2000 Edition</a> (December 21, 2000) <br /> <a href="fall2000/">Fall 2000 Edition</a> (September 21, 2000) <br /> <a href="sum2000/">Summer 2000 Edition</a> (June 21, 2000) <br /> <a href="spr2000/">Spring 2000 Edition</a> (March 21, 2000) <br /> <a href="win1999/">Winter 1999 Edition</a> (December 21, 1999) <br /> <a href="fall1999/">Fall 1999 Edition</a> (September 21, 1999) <br /> <a href="sum1999/">Summer 1999 Edition</a> (June 21, 1999) <br /> <a href="spr1999/">Spring 1999 Edition</a> (March 21, 1999) <br /> <a href="win1998/">Winter 1998 Edition</a> (December 21, 1998) <br /> <a href="fall1998/">Fall 1998 Edition</a> (September 21, 1998) <br /> <a href="sum1998/">Summer 1998 Edition</a> (June 21, 1998) <br /> <a href="spr1998/">Spring 1998 Edition</a> (March 21, 1998) <br /> <a href="win1997/">Winter 1997 Edition</a> (December 21, 1997) <br /> <a href="fall1997/">Fall 1997 Edition</a> (September 21, 1997) </div> <!-- End content --><!--DO NOT MODIFY THIS LINE AND BELOW--> <div id="footer" class="scroll-block"> <div id="footer-menu"> <div class="menu-block"> <h4><i class="icon-book"></i> Browse</h4> <ul role="menu"> <li role="menuitem"><a href="../contents.html">Table of Contents</a></li> <li role="menuitem"><a href="../new.html">What's New</a></li> <li role="menuitem"><a href="https://plato.stanford.edu/cgi-bin/encyclopedia/random">Random Entry</a></li> <li role="menuitem"><a href="../published.html">Chronological</a></li> <li role="menuitem"><a href="../archives/">Archives</a></li> </ul> </div> <div class="menu-block"> <h4><i class="icon-info-sign"></i> About</h4> <ul role="menu"> <li role="menuitem"><a href="../info.html">Editorial Information</a></li> <li role="menuitem"><a href="../about.html">About the SEP</a></li> <li role="menuitem"><a href="../board.html">Editorial Board</a></li> <li role="menuitem"><a href="../cite.html">How to Cite the SEP</a></li> <li role="menuitem"><a href="../special-characters.html">Special Characters</a></li> <li role="menuitem"><a href="../tools/">Advanced Tools</a></li> <li role="menuitem"><a href="../accessibility.html">Accessibility</a></li> <li role="menuitem"><a href="../contact.html">Contact</a></li> </ul> </div> <div class="menu-block"> <h4><i class="icon-leaf"></i> Support SEP</h4> <ul role="menu"> <li role="menuitem"><a href="../support/">Support the SEP</a></li> <li role="menuitem"><a href="../support/friends.html">PDFs for SEP Friends</a></li> <li role="menuitem"><a href="../support/donate.html">Make a Donation</a></li> <li role="menuitem"><a href="../support/sepia.html">SEPIA for Libraries</a></li> </ul> </div> </div> <!-- End footer menu --> <div id="mirrors"> <div id="mirror-info"> <h4><i class="icon-globe"></i> Mirror Sites</h4> <p>View this site from another server:</p> </div> <div class="btn-group open"> <a class="btn dropdown-toggle" data-toggle="dropdown" href="https://plato.stanford.edu/"> <span class="flag flag-usa"></span> USA (Main Site) <span class="caret"></span> <span class="mirror-source">Philosophy, Stanford University</span> </a> <ul class="dropdown-menu"> <li><a href="../mirrors.html">Info about mirror sites</a></li> </ul> </div> </div> <!-- End mirrors --> <div id="site-credits"> <p>The Stanford Encyclopedia of Philosophy is <a href="../info.html#c">copyright © 2024</a> by <a href="https://mally.stanford.edu/">The Metaphysics Research Lab</a>, Department of Philosophy, Stanford University</p> <p>Library of Congress Catalog Data: ISSN 1095-5054</p> </div> <!-- End site credits --> </div> <!-- End footer --> </div> <!-- End container --> <!-- NOTE: Script required for drop-down button to work (mirrors). --> <script> $('.dropdown-toggle').dropdown(); </script> </body> </html>