"There's no rational reason this should not be allowed in."

Its hard to find a rational reason to stop eating meat.

There's no rational reason I can think of for saying it's not good.

I cannot see one rational reason for not allowing it.

Lucy always has a rational reason for what she does, and sometimes it's a good one.

I tried my best to give her a rational reason.

For no rational reason, he was sure that would be a bad choice.

"But if there is a rational reason for what they did, I have yet to find it."

But those reasons, however rational, had occurred to her only after the fact.

There is no rational reason for the current market optimism.