What does London mean when he writes about the " paradox of living" What are his examples of this?

The paradox that Mr. London is describing is that we are most alive when we are most in danger, so very close to dying. It most telling that Mr. London uses Buck's pursuit of the snowshoe hare, which is, in a sense, a white rabbit. To pursue, and kill this rabbit, as part of his struggle to live. This touches on another keypoint of the paradox in that all humans need to kill in order to live. Killing can include both plants and animals.