"agree surely" is a correct and usable phrase in written English
You can use it when you want to show full agreement with a statement. For example: I think we should take a vacation this summer. Agree surely!
Or to put it another way, if we have moral obligations to future, as-yet-unborn generations, as almost everyone seems to agree, surely those duties have to include some obligation for somebody to bring those generations into existence in the first place — to imitate the sacrifices that our parents made, and give another generation the chances that we've had?
Not only is each individual result significant, rejecting the null hypothesis at a probability of one in over three million, the fact that two independent experiments agree surely makes the case for a previously unknown particle at 125 GeV proven beyond a reasonable doubt.
VegasDiamond agreed: "Surely Hardcore History in the number one recommendation!" The show's presenter, Dan Carlin, takes on the most violent and dramatic moments in history, dropping in anecdotes of his own.
I agree – but surely there is more to the psalms than poetry.
Not every birdwatcher would agree, but surely none think badly of this bright-painted little chat.
Much of this, they agree, is surely down to culture, with Ann being encouraged to adopt more genteel middle-class ways.
The Indians would surely agree.
Newt Gingrich would surely agree.
Mr. Mohsin would surely agree.
The Marlins would surely agree.
Many in the crowd of 42,372 would surely agree.
