The meaning of words and phrases - "playing Devil's advocate"

It strikes me that we frequently use words out of tired old habits, without thinking - or meaning- what we say.  I thought it might be fun to occasionally pick a phrase and see if we can explore what's really being said.

So let's start with... "playing Devil's advocate".  Two alternative meanings spring to mind:

"I disagree with you, but I lack the courage or integrity to say so."

OR

"I'm much smarter than you, but so that you don't feel totally dumb, I'll use this phrase to soften the blow."

Any other ideas about the real meaning behind this phrase?

The meaning of words and phrases - "playing Devil's advocate"

It strikes me that we frequently use words out of tired old habits, without thinking - or meaning- what we say.  I thought it might be fun to occasionally pick a phrase and see if we can explore what's really being said.

So let's start with... "playing Devil's advocate".  Two alternative meanings spring to mind:

"I disagree with you, but I lack the courage or integrity to say so."

OR

"I'm much smarter than you, but so that you don't feel totally dumb, I'll use this phrase to soften the blow."

Any other ideas about the real meaning behind this phrase?