I suppose that the authors mean when they say that a successful summary requires “facing two ways at once” means that you have both sides of the argument for it to be successful. Both the side of agreement and the side of disagreement should be included in the summary. You don’t want to be biased when you write your summary. You need to balance the authors writing and come up with a focus and not wander off on different topics. You want it to be relevant and accurate to what you’re writing about. You want to emphasize the most important parts. You don’t want the summary to be inaccurate and don’t put in your own opinion because it can hurt the credibility of it. If you don’t believe what you’re writing about and you aren’t passionate about it then your summary won’t be as real sounding and it will be harder to accomplish and complete. Not just that but you might come across the problem of having to convince yourself to believe it, just to be able to do the writing of it. You have to play a game to where if you disagree with a part of it, you have to write about it as if you believe it. List summaries are where you just list everything, there is no particular order or flow to it. It’s just simply listing and naming things in your summary and it doesn’t get any true point across if you do it like that.