transitory　condensation。
  Despite　its　conjectural　side；　by　virtue　of　which　it　to　some
  extent　escapes　the　severest　form　of　criticism；　history　has　not
  been　free　from　this　universal　revision。　　There　is　no　longer　a
  single　one　of　its　phases　of　which　we　can　say　that　it　is　certainly
  known。　　What　appeared　to　be　definitely　acquired　is　now　once　more
  put　in　question。
  Among　the　events　whose　study　seemed　completed　was　the　French
  Revolution。　　Analysed　by　several　generations　of　writers；　one
  might　suppose　it　to　be　perfectly　elucidated。　　What　new　thing　can
  be　said　of　it；　except　in　modification　of　some　of　its　details？
  And　yet　its　most　positive　defenders　are　beginning　to　hesitate　in
  their　judgments。　　Ancient　evidence　proves　to　be　far　from
  impeccable。　　The　faith　in　dogmas　once　held　sacred　is　shaken。　　The
  latest　literature　of　the　Revolution　betrays　these　uncertainties。
  Having　related；　men　are　more　and　more　chary　of　drawing
  conclusions。
  Not　only　are　the　heroes　of　this　great　drama　discussed　without
  indulgence；　but　thinkers　are　asking　whether　the　new　dispensation
  which　followed　the　ancien　regime　would　not　have　established
  itself　naturally；　without　violence；　in　the　course　of　progressive
  civilisation。　　The　results　obtained　no　longer　seem　in
  correspondence　either　with　their　immediate　cost　or　with　the
  remoter　consequences　which　the　Revolution　evoked　from　the
  possibilities　of　history。
  Several　causes　have　led　to　the　revision　of　this　tragic　period。
  Time　has　calmed　passions；　numerous　documents　have　gradually
  emerged　from　the　archives；　and　the　historian　is　learning　to
  interpret　them　independently。
  But　it　is　perhaps　modern　psychology　that　has　most　effectually
  influenced　our　ideas；　by　enabling　us　more　surely　to　read　men　and
  the　motives　of　their　conduct。
  Among　those　of　its　discoveries　which　are　henceforth　applicable　to
  history　we　must　mention；　above　all；　a　more　profound　understanding
  of　ancestral　influences；　the　laws　which　rule　the　actions　of　the
  crowd；　data　relating　to　the　disaggregation　of　personality；　mental
  contagion；　the　unconscious　formation　of　beliefs；　and　the
  distinction　between　the　various　forms　of　logic。
  To　tell　the　truth；　these　applications　of　science；　which　are
  utilised　in　this　book；　have　not　been　so　utilised　hitherto。
  Historians　have　generally　stopped　short　at　the　study　of
  documents；　and　even　that　study　is　sufficient　to　excite　the　doubts
  of　which　I　have　spoken。
  The　great　events　which　shape　the　destinies　of　peoples
  revolutions；　for　example；　and　the　outbreak　of　religious　beliefs
  are　sometimes　so　difficult　to　explain　that　one　must　limit　oneself
  to　a　mere　statement。
  From　the　time　of　my　first　historical　researches　I　have　been
  struck　by　the　impenetrable　aspect　of　certain　essential　phenomena；
  those　relating　to　the　genesis　of　beliefs　especially；　I　felt
  convinced　that　something　fundamental　was　lacking　that　was
  essential　to　their　interpretation。　　Reason　having　said　all　it
  could　say；　nothing　more　could　be　expected　of　it；　and　other　means
  must　be　sought　of　comprehending　what　had　not　been　elucidated。
  For　a　long　time　these　important　questions　remained　obscure　to　me。
  Extended　travel；　devoted　to　the　study　of　the　remnants　of　vanished
  civilisations；　had　not　done　much　to　throw　light　upon　them。
  Reflecting　upon　it　continually；　I　was　forced　to　recognise　that
  the　problem　was　composed　of　a　series　of　other　problems；　which　I
  should　have　to　study　separately。　　This　I　did　for　a　period　of
  twenty　years；　presenting　the　results　of　my　researches　in　a
  succession　of　volumes。
  One　of　the　first　was　devoted　to　the　study　of　the　psychological
  laws　of　the　evolution　of　peoples。　　Having　shown　that　the
  historic　racesthat　is；　the　races　formed　by　the　hazards　of
  historyfinally　acquired　psychological　characteristics　as　stable
  as　their　anatomical　characteristics；　I　attempted　to　explain　how　a
  people　transforms　its　institutions；　its　languages；　and　its　arts。
  I　explained　in　the　same　work　why　it　was　that　individual
  personalities；　under　the　influence　of　sudden　variations　of
  environment；　might　be　entirely　disaggregated。
  But　besides　the　fixed　collectivities　formed　by　the　peoples；　there
  are　mobile　and　transitory　collectivities　known　as　crowds。　　Now
  these　crowds　or　mobs；　by　the　aid　of　which　the　great　movements　of
  history　are　accomplished；　have　characteristics　absolutely
  different　from　those　of　the　individuals　who　compose　them。　　What
  are　these　characteristics；　and　how　are　they　evolved？　　This　new
  problem　was　examined　in　The　Psychology　of　the　Crowd。
  Only　after　these　studies　did　I　begin　to　perceive　certain
  influences　which　had　escaped　me。
  But　this　was　not　all。　　Among　the　most　important　factors　of
  history　one　was　preponderantthe　factor　of　beliefs。　　How　are
  these　beliefs　born；　and　are　they　really　rational　and　voluntary；
  as　was　long　taught？　　Are　they　not　rather　unconscious　and
  independent　of　all　reason？　　A　difficult　question；　which　I　dealt
  with　in　my　last　book；　Opinions　and　Beliefs。
  So　long　as　psychology　regards　beliefs　as　voluntary　and　rational
  they　will　remain　inexplicable。　　Having　proved　that　they　are
  usually　irrational　and　always　involuntary；　I　was　able　to　propound
  the　solution　of　this　important　problem；　how　it　was　that　beliefs
  which　no　reason　could　justify　were　admitted　without
  difficulty　by　the　most　enlightened　spirits　of　all　ages。
  The　solution　of　the　historical　difficulties　which　had　so　long
  been　sought　was　thenceforth　obvious。　　I　arrived　at　the　conclusion
  that　beside　the　rational　logic　which　conditions　thought；　and　was
  formerly　regarded　as　our　sole　guide；　there　exist　very　different
  forms　of　logic：　affective　logic；　collective　logic；　and　mystic
  logic；　which　usually　overrule　the　reason　and　engender　the
  generative　impulses　of　our　conduct。
  This　fact　well　established；　it　seemed　to　me　evident　that　if　a
  great　number　of　historical　events　are　often　uncomprehended；　it　is
  because　we　seek　to　interpret　them　in　the　light　of　a　logic　which
  in　reality　has　very　little　influence　upon　their　genesis。
  All　these　researches；　which　are　here　summed　up　in　a　few　lines；
  demanded　long　years　for　their　accomplishment。　　Despairing　of
  completing　them；　I　abandoned　them　more　than　once　to　return　to
  those　labours　of　the　laboratory　in　which　one　is　always　sure　of
  skirting　the　truth　and　of　acquiring　fragments　at　least　of
  certitude。
  But　while　it　is　very　interesting　to　explore　the　world　of　material
  phenomena；　it　is　still　more　so　to　decipher　men；　for　which　reason
  I　have　always　been　led　back　to　psychology。
  Certain　principles　deduced　from　my　researches　appearing　likely　to
  prove　fruitful；　I　resolved　to　apply　them　to　the　study　of　concrete
  instances；　and　was　thus　led　to　deal　with　the　Psychology　of
  Revolutionsnotably　that　of　the　French　Revolution。
  Proceeding　in　the　analysis　of　our　great　Revolution；　the
  greater　part　of　the　opinions　determined　by　the　reading　of　books
  deserted　me　one　by　one；　although　I　had　considered　them
  unshakable。
  To　explain　this　period　we　must　consider　it　as　a　whole；　as　many
  historians　have　done。　　It　is　composed　of　phenomena　simultaneous
  but　independent　of　one　another。
  Each　of　its　phases　reveals　events　engendered　by　psychological
  laws　working　with　the　regularity　of　clockwork。　　The　actors　in
  this　great　drama　seem　to　move　like　the　characters　of　a　previously
  determined　drama。　　Each　says　what　he　must　say；　acts　as　he　is
  bound　to　act。
  To　be　sure；　the　actors　in　the　revolutionary　drama　differed　from
  those　of　a　written　drama　in　that　they　had　not　studied　their
  parts；　but　these　were　dictated　by　invisible　forces。
  Precisely　because　they　were　subjected　to　the　inevitable
  progression　of　logics　incomprehensible　to　them　we　see　them　as
  greatly　astonished　by　the　events　of　which　they　were　the　heroes　as
  are　we　ourselves。　　Never　did　they　suspect　the　invisible　powers
  which　forced　them　to　act。　　They　were　the　masters　neither　of　their
  fury　nor　their　weakness。　　They　spoke　in　the　name　of　reason；
  pretending　to　be　guided　by　reason；　but　in　reality　it　was　by　no
  means　reason　that　impelled　them。
  ‘‘The　decisions　for　which　we　are　so　greatly　reproached；''　wrote
  Billaud…Varenne；　‘‘were　more　often　than　otherwise　not　intended　or
  desired　by　us　two　days　or　even　one　day　beforehand：　the　crisis
  alone　evoked　them。''
  Not　that　we　must　consider　the　events　of　the　Revolution　as
  dominated　by　an　imperious　fatality。　　The　readers　of　our　works
  will　know　that　we　recognise　in　the　man　of　superior　qualities　the
  role　of　averting　fatalities。　　But　he　can　dissociate　himself
  only　from　a　few　of　such；　and　is　often　powerless　before　the
  sequence　of　events　which　even　at　their　origin　could　scarcely　be
  ruled。　　The　scientist　knows　how　to　destroy　the　microbe　before　it
  has　time　to　act；　but　he　knows　himself　powerless　to　prevent　the
  evolution　of　the　resulting　malady。
  When　any　question　gives　rise　to　violently　contradictory　opinions
  we　may　be　sur