If once we admit, be it for a single hour or in a single instance, that there can be anything more important than compassion for a fellow human being, then there is no crime against man that we cannot commit with an easy conscience.
There is a common perception that compassion is, if not actually an impediment, at least irrelevant to professional life. Personally, I would argue that not only is it relevant, but that when compassion is lacking, our activities are in danger of becoming destructive. This is because when we ignore the question of the impact our actions have on others' well-being, inevitably we end up hurting them.
The indifference, callousness and contempt that so many people exhibit toward animals is evil first because it results in great suffering in animals, and second because it results in an incalculably great impoverishment of the human spirit.