Agreement and Disagreement

Agreement

There are many reasons for ...

There is no doubt about it that ...

I simply must agree with that.

I am of the same opinion.

I am of the same opinion as the author.

I completely/absolutely agree with the author.

Qualified Disagreement

It is only partly true that...

I can agree with that only with reservations.

That seems obvious, but ...

That is not necessarily so.

It is not as simple as it seems.

Under certain circumstances ...

Disagreement

There is more to it than that.

The problem is that ...

I (very much) doubt whether ...

This is in complete contradiction to ...

What is even worse, ...

I am of a different opinion because ...

I cannot share this / that / the view.

I cannot agree with this idea.

What I object to is ...

Unlike the author I think ...