help. Is this sentence correct? I have got a sentence in my IB diploma textbook. the debatable nature of much ethical knowledge is important to recognize and vital to understanding human behavior. I was confused about the meaning of the sentence. I ask a colleague of mine to figure this out. but my collegue said that she thought this sentence is a kinda incorrect. they right saying is the debatable nature of much ethical knowledge is important to recognize and vital for (replace to with for) understanding human behavior or the debatable nature of much ethical knowledge is important to recognize and vital to understand (delete the ing) human behavior which one of the three sentence above make sense? Thanks a lot.