Poland's dissident movement is distinctive because it cannot be dismissed by the leadership as a narrow fringe of disaffected intellectuals - although that is the way the Polish press has portrayed the Committee for the Defense of the Workers, a group of about 18 persons formed after last summer's worker riots.

Outsiders have focused attention on the committee's efforts to raise money on behalf of workers imprisoned following the riots and its reports on police brutality used in restoring order. The group numbers among its members the distinguished writer Jerzy Andrzejewski and the economist Edward Lipinski.

Yet the response of the leadership to the upheaval - immediate suspension of the price increases, measures to encourage private business and farming, an increase in the output of consumer goods - resulted from much broader-based popular sentiment than the committee represented. Last week Polish leaders said most of the workers arrested in the riots would be given clemency.

With 30 million members in a country of 33 million the Catholic Church speaks in Poland with an authority and impact that no other non-governmental body in Eastern Europe has. To be truly effective, intellectuals must join with the church, as dozens did last spring in effectively opposing amendments to the constitution that many regarded as oppressive. This is politics in Poland and not merely protest.

The authorities in Poland have not disbanded the Committee in Defense of the Workers. The anomalies of such tolerance in Poland have a simple explanation: the leadership recognizes that for now it has to live with opposition.