explain: "nothing so completely verifies our percepition of a thing, as our killing of it.

One of the most important parts of "perceiving" something is to know that it is alive and has the characteristics of something living. When living, we note individual qualities of each person. When we kill something, suddenly all of those individual qualities disappear and we realize that what makes us living people goes away; when one is dead, he or she is dead and that is that.