{"id":209,"date":"2015-05-23T02:03:20","date_gmt":"2015-05-23T02:03:20","guid":{"rendered":"http:\/\/aristotle2digital.blogwyrm.com\/?p=209"},"modified":"2015-05-23T02:03:20","modified_gmt":"2015-05-23T02:03:20","slug":"self-reference-and-paradoxes","status":"publish","type":"post","link":"https:\/\/aristotle2digital.blogwyrm.com\/?p=209","title":{"rendered":"Self-Reference and Paradoxes"},"content":{"rendered":"<p>The essence of the G\u00f6del idea is to encode not just the facts but also the \u2018facts about the facts\u2019 of the formal system being examined within the framework of the system being examined.\u00a0 This meta-mathematics technique allowed G\u00f6del to prove simple facts like \u20182 + 2 = 4\u2019 and hard facts like \u2018not all true statements are axioms or are theorems \u2013 some are simply out of reach of the formal system to prove\u2019 within the context of the system itself.\u00a0 The hard facts come from the system talking about or referring to itself with its own language.<\/p>\n<p>As astonishing as Godel\u2019s theorem is, the concept of paradoxes within self-referential systems is actually a very common experience in natural language.\u00a0 All of us have played at one time or another with odd sentences like \u2018This sentence is false!\u2019.\u00a0 Examined from a strictly mechanical and logical vantage, how should that sentence be parsed?\u00a0 If the sentence is true then it is lying to us.\u00a0 If it is false, then it is sweetly and innocently telling us the truth.\u00a0 This example of the <a href=\"http:\/\/en.wikipedia.org\/wiki\/Liar_paradox\">liar\u2019s paradox<\/a> has been known since antiquity and variation of it have appeared throughout the ages in stories of all sorts.<\/p>\n<p>Perhaps the most famous example comes from the original Star Trek television series in an episode entitled \u2018I Mudd\u2019. In this installment of the ongoing adventures of the starship Enterprise, an impish Captain Kirk defeats a colony of androids that hold him and his crew hostage by exploiting their inability to be meta.<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/wlMegqgGORY\" width=\"420\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>There are actually host of paradoxes (or antinomies in the technical speak) that some dwerping around on the internet can uncover in just a handful of clicks.\u00a0 They all arise when a formal system talks about itself in its own language and often their paradoxical nature arises when they talk about something of a negative nature.\u00a0 The sentence \u2018This sentence is true,\u2019 is fine while \u2018This sentence is false.\u2019 is not.<\/p>\n<p>Not all of the examples show up as either interesting but useless tricks of the spoken language or as formal encodings in mathematical logic.\u00a0 One of the most interesting cases deals with libraries of either the brick and mortar variety or existing solely on hard drives and in RAM and FTP packets.<\/p>\n<p>Consider for a moment that you\u2019ve been given charge of a library.\u00a0 Properly speaking, a library has two basic components: the books to read and a system to catalog and locate the books so that they can be read.\u00a0 Now thinking about the books is no problem.\u00a0 They are the atoms of the system and so can be examined separately or in groups or classes.\u00a0 It is reasonable and natural to talk about a single book like \u2018Moby Dick\u2019 and to catalog this book along with all the other separate works that the library contains.\u00a0 It is also reasonable and natural to talk about all books written by Herman Melville and to catalog them within a new list with a title perhaps with the name \u2018Lists of works by H. Melville\u2019.\u00a0 A similar list can be made with grouping criterion selects books about the books by Melville.\u00a0 This list would have a title like \u2018List of critiques and reviews of the works by H. Melville\u2019.<\/p>\n<p>An obvious extension would be to construct something like the following list.<\/p>\n<p><div style = \"background-color:#ff6666; border: solid 1px black;\">\n<em>List of Author Critiques and Reviews:<\/em><\/p>\n<ul>\n<li>List of critiques and reviews of H. Melville<\/li>\n<li>List of critiques and reviews of J. R. R. Tolkien<\/li>\n<li>List of critiques and reviews of U. Eco<\/li>\n<li>List of critiques and reviews of R. Stout<\/li>\n<li>List of critiques and reviews of G. K. Chesterton<\/li>\n<li>List of critiques and reviews of A. Christie<\/li>\n<li>\u2026.<\/li>\n<\/ul>\n<\/div>\n<p>Since the lists are themselves written works what status do they have in the cataloging system?\u00a0 Should there also be lists of lists?\u00a0 If so, how deep should there construction go?\u00a0\u00a0 At some point won\u2019t we arrive at lists that have to refer to themselves and what do we do when we reach that point? \u00a0Should the library catalog have a reference to itself as a written work?<\/p>\n<p>Bertrand Russell wrestled with these questions in the context of set theory around the turn of the 20<sup>th<\/sup> century.\u00a0 To continue on with the library example, Russell would label the \u2018List of Author Critiques and Reviews\u2019 as a <em>normal set<\/em> since it is a collection of things that doesn\u2019t include itself.\u00a0 He would also label as an <em>abnormal set<\/em>, any list that would have itself as a member \u2013 in this case a catalog (i.e. list) of all lists pertaining to the library.\u00a0 General feeling suggests that the normal sets are well behaved but the abnormal sets are likely to cause problems.\u00a0 So let\u2019s just focus on the normal sets.\u00a0 Russell asks the following question about the normal sets:\u00a0 Is the set, R, of all normal sets, itself normal or abnormal?\u00a0 If R is normal, then it must appear as a member in its own listing, thus making R abnormal.\u00a0 Alternatively, if R is abnormal, it can\u2019t be listed as a member within itself and, therefore, it must be normal.\u00a0 No matter which way you start you are led to a contradiction.<\/p>\n<p>The natural tendency is, at this point, to cry foul and to suggest that the whole thing is being drawn out to an absurd length.\u00a0 Short and simple answers to each of the questions posed in the earlier paragraph come to mind with the application of a little common sense.\u00a0 Lists should only be themselves cataloged if they are independent works that are distinct parts of the library.\u00a0 The overall library catalog need not list itself because it primary function is to help the patron find all the other books, publications, and related works in the library.\u00a0 If the patron can find the catalog, then there is no need to have it listed within itself.\u00a0 One the other hand, if the patron cannot find the catalog, having it listed within itself serves no purpose \u2013 the patron will need something else to point him towards the catalog.<\/p>\n<p>And as far as Russell and perfidious paradox is concerned, who cares?\u00a0 This might be a matter to worry about if one is a stuffy logician who can\u2019t get a date on a Saturday night but normal people (does this mean Russell and his kind are abnormal?) have better things to do with their lives than worry about such ridiculous ideas.<\/p>\n<p>Despite these responses, or maybe because of them, we should care.\u00a0 Application of common sense is actually quite sophisticated even if we are quite unaware of the subtleties involved.\u00a0 In all of these common-sensical responses there is an implicit assumption about something above or outside.\u00a0 If the patron can\u2019t find the library catalog, well then that is what a librarian is for \u2013 to point the way to the catalog.\u00a0 The librarian doesn&#8217;t need to be referred to or listed in the catalog.\u00a0 He sits outside the system and can act as an entry point into the system.\u00a0 If there is a paradox in set theory, not to worry, there are more important things than complete consistency in formal systems.<\/p>\n<p>This is concept of sitting outside the system, is at the heart of the current differences between human intelligence and machine intelligence.\u00a0 The later, codified by the formal rules of logic, can\u2019t resolve these kinds of paradoxes precisely because they can\u2019t step outside themselves like people can. And maybe they never will.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The essence of the G\u00f6del idea is to encode not just the facts but also the \u2018facts about the facts\u2019 of the formal system being examined within the framework of&#8230; <a class=\"read-more-button\" href=\"https:\/\/aristotle2digital.blogwyrm.com\/?p=209\">Read more &gt;<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-209","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=\/wp\/v2\/posts\/209","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=209"}],"version-history":[{"count":0,"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=\/wp\/v2\/posts\/209\/revisions"}],"wp:attachment":[{"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=209"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=209"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aristotle2digital.blogwyrm.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=209"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}