It is true that certain living creatures, as bees and ants, live sociably one with another . . . and yet have no other direction than their particular judgments and appetites; nor speech, whereby one of them can signify to another what he thinks expedient for the common benefit: and therefore some man may perhaps desire to know why mankind cannot do the same.
Thomas Hobbes, Leviathan Chapter 8 (1968).
Any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well developed, or nearly as well developed, as in man.
Charles Darwin, ...