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.
There is more to be learnt from every page of David Hume than from the collected philosophical works of Hegel, Herbart, and Schleiermacher are taken together.
For it is owing to their wonder that men both now begin and at first began to philosophize... They were pursuing science in order to know, and not for any utilitarian end.
I do feel that spiritual progress does demand at some stage that we should cease to kill our fellow creatures for the satisfaction of our bodily wants.