Toavoidthevariousfoolishopinionstowhichmankindisprone,nosuperhumangeniusisrequired.
Afewsimpleruleswillkeepyou,notfromallerror,butfromsillyerror.
Ifthematterisonethatcanbesettledbyobservation,maketheobservationyourself.
Aristotlecouldhaveavoidedthemistakeofthinkingthatwomenhavefewerteeththanmen,bythesimpledeviceofaskingMrs.Aristotletokeephermouthopenwhilehecounted.
Hedidnotdosobecausehethoughtheknew.
Thinkingthatyouknowwheninfactyoudon’tisafatalmistake,towhichweareallprone.
Manymatters,however,arelesseasilybroughttothetestofexperience.
If,likemostofmankind,youhaveconvictionsonmanysuchmatters,therearewaysinwhichyoucanmakeyourselfawareofyourownbias.
Ifanopinioncontrarytoyourownmakesyouangry,thatisasignthatyouaresubconsciouslyawareofhavingnogoodreasonforthinkingasyoudo.
Ifsomeonemaintainsthattwoandtwoarefive,youfeelpityratherthananger.
Themostsavagecontroversiesarethoseaboutmattersastowhichthereisnogoodevidenceeitherway.
Persecutionisusedintheology,notinarithmetic,becauseinarithmeticthereisknowledge,butintheologythereisonlyopinion.
Sowheneveryoufindyourselfgettingangryaboutadifferenceofopinion,beonyourguard;youwillprobablyfind,onexamination,thatyourbeliefisgoingbeyondwhattheevidencewarrants.
Agoodwayofridingyourselfofcertainkindsofdogmatismistobecomeawareofopinionsheldinsocialcirclesdifferentfromyourown.
Seekoutpeoplewithwhomyoudisagree,andreadanewspaperbelongingtoapartythatisnotyours.
Ifthepeopleandthenewspaperseemmadandwicked,remindyourselfthatyouseemsotothem.
Inthisopinionbothpartiesmayberight,buttheycannotbothbewrong.
Thisreflectionshouldgeneratecaution.