Desirism Book - Part 0027 - Against Moral Sentiment Theories

David Hume was mistaken to claim that moral facts depend on our moral sentiments.

We have built a proto-moral community based substantially on David Hume's theory of action. It is a community built by agents where desires alone provide the ends or goals of intentional action, and where reason "is the slave of the passions". That is to say, the job of reason is to find the most effective ways to serve those desires.

However, when Hume went from this to his theory of morality he made a mistake.

Recall that our proto-moral community consists of Alphs (who desire to gather stones) and Betts (who desire to scatter stones). Alphs and Betts both have an aversion to pain, and a capacity to acquire new desires as a consequence of praise and condemnation. The universal aversion to pain gives people reason to use condemnation to promote a universal aversion to that which will cause pain in others.

I have also given this community the verbal tradition of using the phrase, "causing harm to others is wrong" both to identify that which people generally have reason to condemn, and as a statement of condemnation.

There is a fact of the matter as to whether people generally have reason to condemn those who cause pain to others which is independent of anybody's beliefs or sentiments about that fact. A person who does not know that condemnation will create in others an aversion to causing pain may not do so. However, this is a case of the agent not being aware of the fact that he has a reason to do something - a mistake of fact, not a case in which causing pain to others becomes permissible.

Hume bases his theory of morality on the sentiments.

Specifically, to know whether something is permissible or impermissible the agent must make himself aware of all of the relevant facts, then use his imagination to remove any personal harm or benefit and any harm or benefit to others with whom she may have a relationship. They then apply their sentiment to this imagined state of affairs, where a sentiment of approval means that the act is permissible or obligatory, and a sentiment of disapproval means that the act is prohibited.

If an agent in our proto-moral system were to go through this exercise they would be indifferent to any pain inflicted on people other than themselves. All they have is a desire to gather or scatter stones and an aversion to their own pain. Neither of these give them a reason to be concerned with a state in which somebody else is made to experience pain. Given their sentiments, they would react to such news with total indifference.

However, even without this sentiment, the agents in this proto-moral world have a reason to condemn those who cause pain. They have reason to promote a universal aversion to causing pain to others. This fact does not spring from any appeal to sentiment. It springs from the propositions that the agent has an aversion to pain, the agent has an ability to promote an aversion to causing pain to others through condemnation, and those who have an aversion to causing pain to others are less likely to act in ways that would cause the agent to experience pain.

Please note that, even though the moral fact of the matter can be discovered through reason alone, it is a fact that relates states of affairs to desires. Or, more precisely, it is a fact that relates a state of affairs where people generally have an aversion to causing pain to agents' aversion to pain. There can be no value without desires. However, the value that comes from desires is a value that reason alone can discover.

Morality does not require any type of moral sentiment.