A Moral philosopher (n.) is the opposite of a Puritan — he treats morality as a question mark; should moralizing not be immoral?
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A Moral philosopher (n.) is like a chemist who can experiment on anyone's practical reason: add the moral law to a will tempted to lie for gain, and reason drops the advantage as acid drops lime for alkali, leaving it at the bottom to be weighed.
Definition.com
A Moral philosopher (n.) who lacks mathematics must dissect the examples of morally judging reason by repeated experiments on common understanding, separating the empirical from the rational as chemistry separates substances.