The Abolitionist Approach links the moral status of nonhumans with sentience alone and not with any other cognitive characteristic; all sentient beings are equal for the purpose of not being used exclusively as a resource.
Sentience is subjective awareness; there is someone who perceives and experiences the world. A sentient being has interests; that is, preferences, wants, or desires. If a being is sentient, then that is necessary and sufficient for the being to have the right not to be used as a means to human ends. The recognition of this right imposes on humans the moral obligation not to use that being as a resource. It is not necessary for a sentient being to have humanlike cognitive characteristics in order to be accorded the right not to be used as property.