P1: All drunks are poor at reason.
P2: All philosophers are drunks.
C: All philosophers are poor at reason.
This is an example of a categorical syllogism using the form AAA-1 (known as Barbara).
The argument is valid though not necessarily sound.
An argument is considered to be valid if the conclusion necessarily follows from the premises.
(IF the premises are true THEN the conclusion must be true.)
An argument is considered to be sound if it is valid AND both of the premises are true.
Here are some links to web sites that discuss categorical syllogisms:

