IfearImayhavemadealongerexcursusthanwasnecessary，andthatfewerwordswouldhavedispelledtheuneasinesswhichmayhavearisenamongsomeofyouasIannouncedmypathologicalprogramme。Atanyrateyoumustallbereadynowtojudgethereligiouslifebyitsresultsexclusively，andIshallassumethatthebugabooofmorbidoriginwillscandalizeyourpietynomore。
Still，youmayaskme，ifitsresultsaretobethegroundofourfinalspiritualestimateofareligiousphenomenon，whythreatenusatallwithsomuchexistentialstudyofitsconditions？Whynotsimplyleavepathologicalquestionsout？
TothisIreplyintwoways。First，Isay，irrepressiblecuriosityimperiouslyleadsoneon；andIsay，secondly，thatitalwaysleadstoabetterunderstandingofathing’ssignificancetoconsideritsexaggerationsandperversionsitsequivalentsandsubstitutesandnearestrelativeselsewhere。Notthatwemaytherebyswampthethinginthewholesalecondemnationwhichwepassonitsinferiorcongeners，butratherthatwemaybycontrastascertainthemorepreciselyinwhatitsmeritsconsist，bylearningatthesametimetowhatparticulardangersofcorruptionitmayalsobeexposed。
Insaneconditionshavethisadvantage，thattheyisolatespecialfactorsofthementallife，andenableustoinspectthemunmaskedbytheirmoreusualsurroundings。Theyplaythepartinmentalanatomywhichthescalpelandthemicroscopeplayintheanatomyofthebody。Tounderstandathingrightlyweneedtoseeitbothoutofitsenvironmentandinit，andtohaveacquaintancewiththewholerangeofitsvariations。Thestudyofhallucinationshasinthiswaybeenforpsychologiststhekeytotheircomprehensionofnormalsensation，thatofillusionshasbeenthekeytotherightcomprehensionofperception。Morbidimpulsesandimperativeconceptions，“fixedideas。”socalled，havethrownafloodoflightonthepsychologyofthenormalwill；andobsessionsanddelusionshaveperformedthesameserviceforthatofthenormalfacultyofbelief。
Similarly，thenatureofgeniushasbeenilluminatedbytheattempts，ofwhichIalreadymademention，toclassitwithpsychopathicalphenomena。Borderlandinsanity，crankiness，insanetemperament，lossofmentalbalance，psychopathicdegenerationtouseafewofthemanysynonymsbywhichithasbeencalled，hascertainpeculiaritiesandliabilitieswhich，whencombinedwithasuperiorqualityofintellectinanindividual，makeitmoreprobablethathewillmakehismarkandaffecthisage，thanifhistemperamentwerelessneurotic。