CHAPTERIV
ITisevidentthathereThucydidesisreadytoadmitthevarietyofmanifestationswhichexternalcausesbringaboutintheirworkingsontheuniformcharacterofthenatureofman.Yet，afterallissaid，theseareperhapsbutverygeneralstatements：theordinaryeffectsofpeaceandwararedwelton，butthereisnorealanalysisoftheimmediatecausesandgenerallawsofthephenomenaoflife，nordoesThucydidesseemtorecognisethetruththatifhumanityproceedsincircles，thecirclesarealwayswidening.
Perhapswemaysaythatwithhimthephilosophyofhistoryispartlyinthemetaphysicalstage，andsee，intheprogressofthisideafromHerodotustoPolybius，theexemplificationoftheComtianLawofthethreestagesofthought，thetheological，themetaphysical，andthescientific：fortrulyoutofthevaguenessoftheologicalmysticismthisconceptionwhichwecallthePhilosophyofHistorywasraisedtoascientificprinciple，accordingtowhichthepastwasexplainedandthefuturepredictedbyreferencetogenerallaws.
Now，justastheearliestaccountofthenatureoftheprogressofhumanityistobefoundinPlato，soinhimwefindthefirstexplicitattempttofoundauniversalphilosophyofhistoryuponwiderationalgrounds.Havingcreatedanideallyperfectstate，thephilosopherproceedstogiveanelaboratetheoryofthecomplexcauseswhichproducerevolutions，ofthemoraleffectsofvariousformsofgovernmentandeducation，oftheriseofthecriminalclassesandtheirconnectionwithpauperism，and，inaword，tocreatehistorybythedeductivemethodandtoproceedfromAPRIORI
psychologicalprinciplestodiscoverthegoverninglawsoftheapparentchaosofpoliticallife.