minds；　because；　without　the　unpleasant　process　of　fining　or
  imprisoning　anybody；　it　maintains　all　prevailing　opinions　outwardly
  undisturbed；　while　it　does　not　absolutely　interdict　the　exercise　of
  reason　by　dissentients　afflicted　with　the　malady　of　thought。　A
  convenient　plan　for　having　peace　in　the　intellectual　world；　and
  keeping　all　things　going　on　therein　very　much　as　they　do　already。
  But　the　price　paid　for　this　sort　of　intellectual　pacification　is　the
  sacrifice　of　the　entire　moral　courage　of　the　human　mind。　A　state　of
  things　in　which　a　large　portion　of　the　most　active　and　inquiring
  intellects　find　it　advisable　to　keep　the　general　principles　and
  grounds　of　their　convictions　within　their　own　breasts；　and　attempt；　in
  what　they　address　to　the　public；　to　fit　as　much　as　they　can　of　their
  own　conclusions　to　premises　which　they　have　internally　renounced；
  cannot　send　forth　the　open；　fearless　characters；　and　logical；
  consistent　intellects　who　once　adorned　the　thinking　world。　The　sort　of
  men　who　can　be　looked　for　under　it；　are　either　mere　conformers　to
  commonplace；　or　time…servers　for　truth；　whose　arguments　on　all　great
  subjects　are　meant　for　their　hearers；　and　are　not　those　which　have
  convinced　themselves。　Those　who　avoid　this　alternative；　do　so　by
  narrowing　their　thoughts　and　interests　to　things　which　can　be　spoken
  of　without　venturing　within　the　region　of　principles；　that　is；　to
  small　practical　matters；　which　would　come　right　of　themselves；　if
  but　the　minds　of　mankind　were　strengthened　and　enlarged；　and　which
  will　never　be　made　effectually　right　until　then：　while　that　which
  would　strengthen　and　enlarge　men's　minds；　free　and　daring
  speculation　on　the　highest　subjects；　is　abandoned。
  Those　in　whose　eyes　this　reticence　on　the　part　of　heretics　is　no
  evil　should　consider；　in　the　first　place；　that　in　consequence　of　it
  there　is　never　any　fair　and　thorough　discussion　of　heretical　opinions；
  and　that　such　of　them　as　could　not　stand　such　a　discussion；　though
  they　may　be　prevented　from　spreading；　do　not　disappear。　But　it　is
  not　the　minds　of　heretics　that　are　deteriorated　most　by　the　ban　placed
  on　all　inquiry　which　does　not　end　in　the　orthodox　conclusions。　The
  greatest　harm　done　is　to　those　who　are　not　heretics；　and　whose　whole
  mental　development　is　cramped；　and　their　reason　cowed；　by　the　fear
  of　heresy。　Who　can　compute　what　the　world　loses　in　the　multitude　of
  promising　intellects　combined　with　timid　characters；　who　dare　not
  follow　out　any　bold；　vigorous；　independent　train　of　thought；　lest　it
  should　land　them　in　something　which　would　admit　of　being　considered
  irreligious　or　immoral？　Among　them　we　may　occasionally　see　some　man　of
  deep　conscientiousness；　and　subtle　and　refined　understanding；　who
  spends　a　life　in　sophisticating　with　an　intellect　which　he　cannot
  silence；　and　exhausts　the　resources　of　ingenuity　in　attempting　to
  reconcile　the　promptings　of　his　conscience　and　reason　with
  orthodoxy；　which　yet　he　does　not；　perhaps；　to　the　end　succeed　in
  doing。
  No　one　can　be　a　great　thinker　who　does　not　recognise；　that　as　a
  thinker　it　is　his　first　duty　to　follow　his　intellect　to　whatever
  conclusions　it　may　lead。　Truth　gains　more　even　by　the　errors　of　one
  who；　with　due　study　and　preparation；　thinks　for　himself；　than　by　the
  true　opinions　of　those　who　only　hold　them　because　they　do　not　suffer
  themselves　to　think。　Not　that　it　is　solely；　or　chiefly；　to　form
  great　thinkers；　that　freedom　of　thinking　is　required。　On　the　contrary；
  it　is　as　much　and　even　more　indispensable　to　enable　average　human
  beings　to　attain　the　mental　stature　which　they　are　capable　of。　There
  have　been；　and　may　again　be；　great　individual　thinkers　in　a　general
  atmosphere　of　mental　slavery。　But　there　never　has　been；　nor　ever
  will　be；　in　that　atmosphere　an　intellectually　active　people。　Where　any
  people　has　made　a　temporary　approach　to　such　a　character；　it　has
  been　because　the　dread　of　heterodox　speculation　was　for　a　time
  suspended。　Where　there　is　a　tacit　convention　that　principles　are　not
  to　be　disputed；　where　the　discussion　of　the　greatest　questions　which
  can　occupy　humanity　is　considered　to　be　closed；　we　cannot　hope　to　find
  that　generally　high　scale　of　mental　activity　which　has　made　some
  periods　of　history　so　remarkable。　Never　when　controversy　avoided　the
  subjects　which　are　large　and　important　enough　to　kindle　enthusiasm；
  was　the　mind　of　a　people　stirred　up　from　its　foundations；　and　the
  impulse　given　which　raised　even　persons　of　the　most　ordinary　intellect
  to　something　of　the　dignity　of　thinking　beings。　Of　such　we　have　had　an
  example　in　the　condition　of　Europe　during　the　times　immediately
  following　the　Reformation；　another；　though　limited　to　the　Continent
  and　to　a　more　cultivated　class；　in　the　speculative　movement　of　the
  latter　half　of　the　eighteenth　century；　and　a　third；　of　still　briefer
  duration；　in　the　intellectual　fermentation　of　Germany　during　the
  Goethian　and　Fichtean　period。　These　periods　differed　widely　in　the
  particular　opinions　which　they　developed；　but　were　alike　in　this；　that
  during　all　three　the　yoke　of　authority　was　broken。　In　each；　an　old
  mental　despotism　had　been　thrown　off；　and　no　new　one　had　yet　taken　its
  place。　The　impulse　given　at　these　three　periods　has　made　Europe　what
  it　now　is。　Every　single　improvement　which　has　taken　place　either　in
  the　human　mind　or　in　institutions；　may　be　traced　distinctly　to　one
  or　other　of　them。　Appearances　have　for　some　time　indicated　that　all
  three　impulses　are　well　nigh　spent；　and　we　can　expect　no　fresh　start
  until　we　again　assert　our　mental　freedom。
  Let　us　now　pass　to　the　second　division　of　the　argument；　and
  dismissing　the　supposition　that　any　of　the　received　opinions　may　be
  false；　let　us　assume　them　to　be　true；　and　examine　into　the　worth　of
  the　manner　in　which　they　are　likely　to　be　held；　when　their　truth　is
  not　freely　and　openly　canvassed。　However　unwillingly　a　person　who
  has　a　strong　opinion　may　admit　the　possibility　that　his　opinion　may　be
  false；　he　ought　to　be　moved　by　the　consideration　that；　however　true　it
  may　be；　if　it　is　not　fully；　frequently；　and　fearlessly　discussed；　it
  will　be　held　as　a　dead　dogma；　not　a　living　truth。
  There　is　a　class　of　persons　（happily　not　quite　so　numerous　as
  formerly）　who　think　it　enough　if　a　person　assents　undoubtingly　to　what
  they　think　true；　though　he　has　no　knowledge　whatever　of　the　grounds　of
  the　opinion；　and　could　not　make　a　tenable　defence　of　it　against　the
  most　superficial　objections。　Such　persons；　if　they　can　once　get
  their　creed　taught　from　authority；　naturally　think　that　no　good；　and
  some　harm；　comes　of　its　being　allowed　to　be　questioned。　Where　their
  influence　prevails；　they　make　it　nearly　impossible　for　the　received
  opinion　to　be　rejected　wisely　and　considerately；　though　it　may　still
  be　rejected　rashly　and　ignorantly；　for　to　shut　out　discussion　entirely
  is　seldom　possible；　and　when　it　once　gets　in；　beliefs　not　grounded
  on　conviction　are　apt　to　give　way　before　the　slightest　semblance　of　an
  argument。　Waiving；　however；　this　possibility…　assuming　that　the　true
  opinion　abides　in　the　mind；　but　abides　as　a　prejudice；　a　belief
  independent　of；　and　proof　against；　argument…　this　is　not　the　way　in
  which　truth　ought　to　be　held　by　a　rational　being。　This　is　not
  knowing　the　truth。　Truth；　thus　held；　is　but　one　superstition　the　more；
  accidentally　clinging　to　the　words　which　enunciate　a　truth。
  If　the　intellect　and　judgment　of　mankind　ought　to　be　cultivated；　a
  thing　which　Protestants　at　least　do　not　deny；　on　what　can　these
  faculties　be　more　appropriately　exercised　by　any　one；　than　on　the
  things　which　concern　him　so　much　that　it　is　considered　necessary　for
  him　to　hold　opinions　on　them？　If　the　cultivation　of　the
  understanding　consists　in　one　thing　more　than　in　another；　it　is　surely
  in　learning　the　grounds　of　one's　own　opinions。　Whatever　people
  believe；　on　subjects　on　which　it　is　of　the　first　importance　to　believe
  rightly；　they　ought　to　be　able　to　defend　against　at　least　the　common
  objections。　But；　some　one　may　say；　〃Let　them　be　taught　the　grounds
  of　their　opinions。　It　does　not　follow　that　opinions　must　be　merely
  parroted　because　they　are　never　heard　controverted。　Persons　who
  learn　geometry　do　not　simply　commit　the　theorems　to　memory；　but
  understand　and　learn　likewise　the　demonstrations；　and　it　would　be
  absurd　to　say　that　they　remain　ignorant　of　the　grounds　of
  geometrical　truths；　because　they　never　hear　any　one　deny；　and
  attempt　to　disprove　them。〃　Undoubtedly：　and　such　teaching　suffices
  on　a　subject　like　mathematics；　where　there　is　nothing　at　all　to　be
  said　on　the　wrong　side　of　the　question。　The　peculiarity　of　the
  evidence　of　mathematical　truths　is　that　all　the　argument　is　on　one
  si