Vivisection originated from the materialistic way of thinking which is destitute of any intuition which cannot look in the works of life. This way of thinking must look at the body as a mechanical interaction of the single parts. Then it is quite natural that one takes the animal experiment where one believes that the same interaction takes place as with the human being to recognise and combat certain illness processes. Only who knows nothing about the real life can do vivisection.
A time comes when the human beings figure out the single life of a creature in connection with the life of the whole universe. The human beings get reverence for life. Then they learn to realise: any life that is taken away from a living being, any harm that is caused to a living being lessens the noblest forces of our own human nature because of a connection which exists between life and life.
Source: Rudolf Steiner – GA 53 – Origin and Goal of the Human Being – Lecture XXII – Berlin, 25th May 1905