The development of nineteenth century medical ethics seems to parallel the legal principles of Blackstone. Very influential during the early nineteenth century was Thomas Percival's Medical Ethics in which the following was written: "To extinguish the first spark of life is a crime of the same nature, both against our maker and society, as to destroy an infant, a child, or a man. '" These views explain in part the condemnation of abortion as the destruction of "human life" by the American Medical Association at its 1859 annual meeting.