In both cases he came up with a perfectly cogent reason for doing so.

But there is a more cogent reason for objection to the death penalty in this or any other case.

But he had no cogent reason why that would have worked better.

I can't think of any cogent reason why that choice was not the best.

He paused, then added, "Those are among the most cogent reasons for my belief that she is not human."

But you haven't given your most cogent reason for staying on Earth.

There is a sound and cogent reason and I'll explain on the way.

But there is a more cogent reason, I believe.

But there were cogent reasons why he ought to make the true situation clear, first and foremost because his own future was involved.

Please understand that I have cogent reasons for wanting his death so described.