He thinks that war is a necessary evil.

That information is unnecessary.

That information is completely unnecessary.

His nature is very kind.

Detailed information is needed to understand the nature of that project.

I was moved by his sincerity.

His nature is very kind.

He is good at writing school essays about his impressions of a book.

Fundamental interaction is one of the most important forces in physics.

Natural language understanding is an important field of artificial intelligence.