For the heart to truly share another's being, it must be an embodied heart, prepared to encounter directly the embodied heart of another. I have met the “other” in this way, not once or a few times, but over and over during years spent in the company of “persons” like you and me, who happen to be nonhuman.
There were 140 baboons in the troop, and I came to know every one as a highly distinctive individual. Each one had a particular gait, which allowed me to know who was who, even from great distances when I couldn't see anyone's face. Every baboon had a characteristic voice and unique things to say with it; each had a face like no other, favorite foods, favorite friends, favorite bad habits.
When a human being relates to an individual nonhuman being as an anonymous object, rather than as a being with its own subjectivity, it is the human, and not the other animal, who relinquishes personhood.
My own life has convinced me that the limitations most of us encounter in our relations with other animals reflect not their shortcomings, as we so often assume, but our own narrow views about who they are and the kinds of relationships we can have with them. And so I conclude by urging anyone with an interest in animal rights to open your heart to the animals around you and find out for yourself what it's like to befriend a nonhuman person.