He is a naive realist.

She has a naive realist perspective on life.

Her naiveite was evident in her trusting nature.

Her naiveté was endearing.

Her naivete was endearing.

Her naivety was evident in her trusting nature.

She had many naivetes when she first started working in the city.

The conference attendees discussed the various naiveites they encountered in their research.

She was unaware of the naivetés of her actions.

She is naiver than her sister.