Why should moral distinction be made between death by the spirochete and death by the streptococcus? – Martin H. Fischer (1879–1962) [Spirochete because of its association with

The world of empirical morality consists for the most part of nothing but ill will and envy. – Goethe

The laws of conscience, which we pretend to be derived from nature, proceed from custom. – Michel de Montaigne, translated

Our morality seems to be only a check on the ultimate domination of force, just as our politeness is a check on the impulse of every pig to put his feet in the trough. – Oliver Wendell Holmes, Jr.