Wehavetoaskhow，onUtilitarianprinciples，thisinfluenceistobeexercised。HereIshallassumethat，forhumanbeingsgenerally，lifeontheaverageyieldsapositivebalanceofpleasureoverpain。Thishasbeendeniedbythoughtfulpersons:butthedenialseemstomeclearlyopposedtothecommonexperienceofmankind，asexpressedintheircommonlyacceptedprinciplesofaction。Thegreatmajorityofmen，inthegreatmajorityofconditionsunderwhichhumanlifeislived，certainlyactasifdeathwereoneoftheworstofevils，forthemselvesandforthosewhomtheylove:andtheadministrationofcriminaljusticeproceedsonasimilarassumption。
Assuming，then，thattheaveragehappinessofhumanbeingsisapositivequantity，itseemsclearthat，supposingtheaveragehappinessenjoyedremainsundiminished，Utilitarianismdirectsustomakethenumberenjoyingitasgreataspossible。Butifweforeseeaspossiblethatanincreaseinnumberswillbeaccompaniedbyadecreaseinaveragehappinessorviceversa，apointariseswhichhasnotonlyneverbeenformallynoticed，butwhichseemstohavebeensubstantiallyoverlookedbymanyUtilitarians。ForifwetakeUtilitarianismtoprescribe，astheultimateendofaction，happinessonthewhole，andnotanyindividual’shappiness，unlessconsideredasanelementofthewhole，itwouldfollowthat，iftheadditionalpopulationenjoyonthewholepositivehappiness，weoughttoweightheamountofhappinessgainedbytheextranumberagainsttheamountlostbytheremainder。Sothat，strictlyconceived，thepointuptowhich，onUtilitarianprinciples，populationoughttobeencouragedtoincrease，isnotthatatwhichaveragehappinessisthegreatestpossible，asappearstobeoftenassumedbypoliticaleconomistsoftheschoolofMalthus——butthatatwhichtheproductformedbymultiplyingthenumberofpersonslivingintotheamountofaveragehappinessreachesitsmaximum。
ItmaybewellheretomakearemarkwhichhasawideapplicationinUtilitariandiscussion。TheconclusionjustgivenwearsacertainairofabsurditytotheviewofCommonSense；becauseitsshowofexactnessisgrotesquelyincongruouswithourconsciousnessoftheinevitableinexactnessofallsuchcalculationsinactualpractice。
But，thatourpracticalUtilitarianreasoningsmustnecessarilyberough，isnoreasonfornotmakingthemasaccurateasthecaseadmits；andweshallbemorelikelytosucceedinthisifwekeepbeforeourmindasdistinctlyaspossiblethestricttypeofthecalculationthatweshouldhavetomake，ifalltherelevantconsiderationscouldbeestimatedwithmathematicalprecision。
Thereisonemorepointthatremainstobenoticed。Itisevidentthattheremaybemanydifferentwaysofdistributingthesamequantumofhappinessamongthesamenumberofpersons；inorder，therefore，thattheUtilitariancriterionofrightconductmaybeascompleteaspossible，weoughttoknowwhichofthesewaysistobepreferred。ThisquestionisoftenignoredinexpositionsofUtilitarianism。