Ariel Gardner, Mitchell Solomon and Colin Mathews
His monumental Essay Concerning Human Understanding aims to determine the limits of human understanding. Earlier writers such as Chillingworth had argued that human understanding was limited, Locke tries to determine what those limits are. We can, he thinks, know with certainty that God exists. We can also know about morality with the same precision we know about mathematics, because we are the creators of moral and political ideas. In regard to natural substances we can know only the appearances and not the underlying realities which produce those appearances. Still, the atomic hypothesis with its attendant distinction between primary and secondary qualities is the most plausible available hypothesis.