What I think about vivisection is that if people admit that they have the right to take or endanger the life of living beings for the benefit of many, there will be no limit to their cruelty.
With regard to philosophical metaphysics, I always see increasing numbers who have attained to the negative goal, but as yet few who climb a few rungs backwards; one ought to look out, perhaps, over the last steps of the ladder, but not try to stand upon them.