1.The arguer may be right about …, but he seems to neglect (fail) to mention (take into account) that fact that…
2.As opposed to (Contrary to) widely (commonly/generally) held (accepted) belief (ideas/views), I believe (argue that…
3.Although many people believe that …, I doubt (wonder) whether the argument bears much analysis (close examination).
4.The advantages of B outweigh any benefit we gained from (carry more weight than those of / are much greater than) A.
5.Although it is commonly (widely / generally) held (felt / accepted / agreed) that …, it is unlikely to be true that…
6.There is an element of truth in this argument (statement), but it ignores a deeper and more basic (important / essential) fact (reason) that…
7.It is true that (True, / To be sure, / Admittedly,)…, but this is not to say (it is unlikely / it doesn’t follow / it doesn’t mean / it won’t be the case) that…
8.The main (obvious / great) problem (flaw / drawback) with (in) this argument (view / remark) is that it is ignorant of (blind to) the basic (bare) fact that …
9.It would be possible (natural / reasonable) to think (believe / take the view) that…, but it would be absurd (wrong) to claim (argue) that …
