The First Amendment is truly the heart of the Bill of Rights. The Framers balanced its freedoms of religion, speech, press, assembly and petition against the needs of a powerful central government, and decided that in those freedoms lies this nation’s only true security. They were not afraid for men to be free. We should not be.

Hugo Black (1886-1971) American politician and jurist, US Supreme Court Justice (1937-71)

James Madison Lecture, NYU School of Law (1960-02-17)
    (Source)

The inaugural Madison lecture. Reprinted as "The Bill of Rights," NYU Law Review, Vol. 35 (1960-04).