To me a personal attack is when you call the person an unkind name, but asking one to be fair, or try to be consistant in ones reasoning or the scheme of things is not an attack!
But than I never did have a secure handle on my use of the language!
I think this says it well:
The light of the body is the eye: if therefore thine eye be single, thy whole body shall be full of light.
But if thine eye be evil, thy whole body shall be full of darkness. If therefore the light that is in thee be darkness, how great is that darkness!