In the Wizard of Oz, the scarecrow sings, "If I only had a brain." Doesn't he really mean, "If only I had a brain"?
I think the sentence the scarecrow sings actually asks what it would be like if he had only one thing, a brain. That, however, is not what he wants to ask.
The reason I ask is that I am playing off this song in a post I am writing on dualism. I was going to title it, "If Only Souls Had a Brain". But when I listened to the song again, I would need to rewrite it as, "If Souls Only Had a Brain" to do a proper play on the scarecrow's words. I think "If Souls Only Had a Brain" is so poorly written, I will just modify what the scarecrow says, and title my post "If Only Souls Had a Brain".
Maybe the scarecrow would have used better grammar, if only he had a brain!