Alasdair MacIntyre wrote:
...in Hume’s own moral philosophy the transition from is to ought is made and made clearly.
But too much must not be made of this, for Hume is a notoriously inconsistent author.
Yet how does Hume make this transition?
Hume, as we have already seen, argues that when we call an action virtuous or vicious we are saying that it arouses in us a certain feeling, that it pleases us in a certain way.
In what way?
This question Hume leaves unanswered.
He passes on to give an account of why we have the moral rules we do have, why it is this rather than that which we judge virtuous.
The basic terms of this account are utility and sympathy.
Consider for example the account of justice which Hume gives in the Treatise
He begins by asking why we accept and obey rules which it would often be in our interest to break.
He denies that we are by nature so constituted that we have a natural regard for public rather than private interest.
- “In general, it may be affirm’d that there is no such passion in human minds as the love of mankind, merely as such, independent of personal qualities, of services, or of relation to oneself.”48
If private interest would lead us to flout the rules, and we have no natural regard for public interest, how then do the rules come about?
Because it is a fact that without rules of justice there would be no stability of property, and indeed no property, an artificial virtue has been created, that of abiding by the rules of justice, and we exhibit this virtue not perhaps so much because we are aware of the benefit that flows from our observing the rules as because we are conscious of how much we are harmed by others infringing them.
Our long-term benefit from insisting on strict observance of the rules will always outweigh our short-term benefit from breaking them on this occasion.
In the Enquiry
human nature is exhibited as less self-interested.
- “It appears also, that, in our general approbation of character and manners, the useful tendency of the social interests moves us not by any regards to self-interest, but has an influence much more universal and extensive.
It appears that a tendency to public good, and to the promoting of peace, harmony, and order in society does always, by affecting the benevolent principles of our frame, engage us on the side of the social virtues.”49
But what is clear is that Hume’s altered picture of human nature is made to provide the same type of explanation and justification of moral rules.
We are so constituted that we have certain desires and needs; these desires and needs are served by maintaining the moral rules.
Hence their explanation and justification.
In such an account we certainly begin with an is
and end with an ought
From A SHORT HISTORY OF [Western] ETHICS by Alasdair MacIntyre pg 111