The purpose of "Against Heresies" was to refute the teachings of various Gnostic groups; apparently, several Greek merchants had begun an oratorial campaign in Irenaeus' bishopric, teaching that the material world was the accidental creation of an evil god, from which we are to escape by the pursuit of gnosis.
O propósito de Contra as herexías foi refutar os ensinos de diversos grupos gnósticos; aparentemente, varios mercadores gregos comezaran unha campaña oratoria no bispado de Ireneo, ensinando que o mundo material era unha creación accidental dun deus mao, do cal temos que escapar procurando a gnose (coñecemento).