Those mutants were merely fulfilling their biological imperative, as the Doktor liked to say.

Diego thanked him with all his heart, but the captain replied that he was merely fulfilling an obligation.

I am merely fulfilling my moral obligation to the community.

It is as if they are merely fulfilling some kind of long-standing obligation to maintain their bulk.

I'm merely fulfilling an assignment, as I'm sure you are.

They were merely fulfilling their nature - to be sado-erotic.

For his part, Mr. Giuliani said he was merely fulfilling a campaign promise.

She was merely fulfilling her duty as a parent.

Rather, science is merely fulfilling its role within nature as is only possible being an intrinsic part of said nature.

When she dropped dead, she merely fulfilled her own prophecy.