> Very few serious philosophers would disagree with Hume.
Relatively few serious philosophers disagree with the positive component of Hume's claim: that reason is (for many people, at least) the slave the passions. On the other hand, many philosophers disagree with the normative component: that reason ought to be the slave of the passions, or that it must be so. Hume himself has a thing or two to say about juxtaposing is-ought claims in such a manner ;)
Of course, you're absolutely right about non-philosophers using "reason" and "logic" as a rhetorical cudgels. We should recognize their (poetically) broken and faithless reasoning and point it out as such.
> I don't think you will find Hume actually arguing this. People read this into him because they glide so easily from is to ought.
I don't disagree with the second part. But the ought is explicit in THN, like 'n4r9 says below. I can think of two (definitely not the only two) plausible interpretations:
1. Reason is necessarily the slave of the passions. If so, there is no sensible way in which it ought be, since normative claims require that a thing could be otherwise. If Hume truly means that, then his "ought" is probably more of an admonishment against trying (and inevitably failing) to usurp the passions. This is a different sense, but I think it's close enough in kind to justify the interpretation.
2. Reason't isn't necessarily the slave of the passions. This makes the "ought" clause more intelligible from my position, but isn't really supported by Hume's account of moral action (i.e., how we find ourselves driven to it).
> This is a factual, not a normative claim.
It's normative in the context of the "admonishment" interpretation above. But yeah, not from #2.
Relatively few serious philosophers disagree with the positive component of Hume's claim: that reason is (for many people, at least) the slave the passions. On the other hand, many philosophers disagree with the normative component: that reason ought to be the slave of the passions, or that it must be so. Hume himself has a thing or two to say about juxtaposing is-ought claims in such a manner ;)
Of course, you're absolutely right about non-philosophers using "reason" and "logic" as a rhetorical cudgels. We should recognize their (poetically) broken and faithless reasoning and point it out as such.