An intellectual is a person who USES intelligence (thought and reason) and critical or analytical thinking, either in a professional or a personal capacity.

知识分子是在职业或个人领域，运用智慧(思考和理性)，并运用批判性或分析性思考的人。

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This showed me plainly that he thought the heroes of the story were men of great intelligence.

VOA: special.2009.08.29

Speaking to reporters at the Pentagon, Secretary Gates said the U.S.intelligence community believes that Iran has been slower to develop its intercontinental ballistic missile capabilities than previously thought.

VOA: standard.2009.09.17

But the only signal I've ever seen where one serious group of British intelligence thought it might be about to happen was there.

BBC

Israeli military intelligence is thought to be monitoring the area via satellite for any movement of weapons outside Syria's borders.

BBC: Q&A: Israeli 'strike' on Syria

This claim, though now seen as incorrect, had come in from an intelligence source thought at the time to be reliable, while the dossier was being compiled.

ECONOMIST: Blair survives an ordeal | The