I agree, but there's something of a psychological barrier to upvoting something I disagree with. Perhaps two sets of arrows -- one for if we like it or not, an

I agree, but there's something of a psychological barrier to upvoting something I disagree with. Perhaps two sets of arrows -- one for if we like it or not, and another for if we think it adds to this discussion. This would make it much easier to not feel "bad" for upvoting or downvoting something against our personal tastes, since we know the button is specifically for it.