withourselves...butwhateverbetheirdegreeoftalentitis
no measureof theirrights. Because SirIsaacNewton was
superiortoothersinunderstanding,hewasnotthereforelord
of the property or persons of others.^2
Similarly,wheninthe1850sthecallforwomen’srightswas
raised in the United States, a remarkable black feminist
namedSojournerTruthmadethesamepointinmorerobust
terms at a feminist convention:
Theytalkaboutthisthinginthehead;whatdotheycallit?
[“Intellect,” whispered someone nearby.] That’sit. What’s
thatgottodowithwomen’srightsorNegroes’rights?Ifmy
cupwon’tholdbutapintandyoursholdsaquart,wouldn’t
you be mean not to let me have my little half-measure full?^3
Itisonthisbasisthatthecaseagainstracismandthecase
against sexism must both ultimately rest; and it is in
accordancewiththisprinciplethattheattitudethatwemay
call “speciesism,” by analogy with racism, must also be
condemned.Speciesism—thewordisnot anattractiveone,
butIcanthinkofnobetterterm—isaprejudiceorattitudeof
biasinfavoroftheinterestsofmembersofone’sownspecies
andagainstthoseofmembersofotherspecies.Itshouldbe
obviousthatthefundamentalobjectionstoracismandsexism
madebyThomasJeffersonandSojournerTruthapplyequally
to speciesism.Ifpossessing ahigherdegreeof intelligence
doesnotentitleonehumantouseanotherforhisorherown
ends,howcanitentitlehumanstoexploitnonhumansforthe
same purpose?^4
Many philosophers and other writers have proposed the
principleofequalconsiderationofinterests,insomeformor