[MD] Putnam on Is-Ought and Truth

[Horse]

If [it is true that]
Blackbeard is a pirate
And If [it is true that]
All pirates are murderers
then
Blackbeard ought to be a murderer

But as not all pirates are murderers P2 is not true so conclusion is false.

However if P2 was true then it would follow that Blackbeard ought to be 
a murderer - in the sense that that would be a requirement of being a 
pirate and not necessarily that it's a good thing to be a murderer. 
Different sorts of oughts.

On 28/04/2010 23:47, craigerb at comcast.net wrote:
> Blackbeard is a pirate.
> All pirates are murderers.
> :. Blackbeard ought to be a murderer.
>
>    

-- 

Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but to skid in sideways, chocolate in one hand, wine in the other, body thoroughly used up, totally worn out and screaming "WOO HOO what a ride!"... Hunter S Thompson