infinitive phrases vs. gerunds

A student in my university class interrupted my gerunds lesson. I had written

"I think that being kind is important."

on the board as an example of correct usage of gerunds. My student wanted to know if

"I think that to be kind is important."

was also correct. It didn't sound right to me, but on reflection I couldn't say with certainty that it is wrong.

What do you think?

PS. My student is still waiting for me to explain it to him.

Noth of the sentences you mentiond are correct, but
'being kind' is more common than 'to be kind' in that
sense.

The concept that you want to look up is the 'object complement.'
Some verbs take only infinitives as objects, some take only
gerunds, and some like 'to be' take either.

More hair splitting that will not help students learn to speak and use English. The time your student spends on this point would be far better spent on the real language, on interesting content,listening, reading, observing the language, noting key phrases and writing. Free the learners from the tyranny of language teachers trying to impose their "knowledge" on the unfortunate learner who really only needs to become fluent in the language.

Are you assuming the student to be an ESL student? For all we know they might be a native speaker studying English grammar (it was a university class after all). Perhaps they're already fine as far as speaking and using English is concerned and are in fact interested in hair splitting.

I agree with D, they're both correct but the second is uncommon. There's be nothing strange, though, about "I think that it is important to be kind."