Editing David Hume (section)

=== Ethics ===
{{see also|is–ought problem}}
Hume's writings on ethics began in the 1740 ''[[A Treatise of Human Nature|Treatise]]'' and were refined in his ''[[An Enquiry Concerning the Principles of Morals]]'' (1751). He understood ''feeling'', rather than ''knowing'', as that which governs ethical actions, stating that "moral decisions are grounded in moral sentiment."{{sfn|Cranston|2014|p=4}} Arguing that reason cannot be behind morality, he wrote:{{sfn|Hume|1739|p=458}}

<blockquote>
Morals excite passions, and produce or prevent actions. Reason itself is utterly impotent in this particular. The rules of morality, therefore, are not conclusions of our reason.
</blockquote>

Hume's [[Moral sense theory|''moral sentimentalism'']] was shared by his close friend [[Adam Smith]],{{sfn|Hume|2013|p=548}}{{failed verification|date=March 2015}} and the two were mutually influenced by the moral reflections of their older contemporary, [[Francis Hutcheson (philosopher)|Francis Hutcheson]].{{sfn|Taylor|1965|p=?}} [[Peter Singer]] claims that Hume's argument that morals cannot have a rational basis alone "would have been enough to earn him a place in the history of ethics."{{sfn|Singer|2015}}

Hume also put forward the ''[[is–ought problem]]'', later known as ''Hume's Law'',{{sfn|Singer|2015}} denying the possibility of logically deriving what ''ought'' to be from what ''is''. According to the ''Treatise'' (1740), in every system of morality that Hume has read, the author begins by stating facts about the world as it ''is'' but always ends up suddenly referring to what ''ought'' to be the case. Hume demands that a reason should be given for inferring what ''ought to be'' the case, from ''what is'' the case. This is because it "seems altogether inconceivable, how this new relation can be a deduction from others."{{sfn|Hume|1739|p=470}}

Hume's theory of ethics has been influential in modern-day [[Meta-ethics|meta-ethical theory]],{{sfn|Edwards|2002|loc=[https://books.google.com/books?id=0pGKAgAAQBAJ&dq=Hume++meta-ethics+influence&pg=PA44 p. 44]}} helping to inspire [[emotivism]],{{sfn|Humber|2008|loc=[https://books.google.com/books?id=dh-E6oIlCkAC&dq=Hume+emotivism+influence&pg=PA136 p. 136]}} and ethical [[expressivism]] and [[non-cognitivism]],{{sfn|Brown|2005|pp=97–100}}{{failed verification|date=March 2015}} as well as [[Allan Gibbard]]'s general theory of moral judgment and judgments of rationality.{{sfn|Angier|2012|loc=[https://books.google.com/books?id=ndyMavMbiZMC&dq=Hume++influence+gibbard&pg=PA114 p. 114]}}