BENJAMIN S. ROSENTHAL of Queens was an able, issue-minded legislator and among the most conscientious of the breed. Arriving in the House in 1962, he established himself as a hard- driving advocate of a full range of liberal Democratic causes, domestic and foreign. In an affectionate tribute, his constituents voted him another term last November although they knew he was a cancer patient. He died Tuesday, at age 59.

Ben Rosenthal was no shrinking violet, no TV smoothie, no seeker of consensus. He believed in fighting hard for the things he cared about, and he did so with a vigor--often witty, but sometimes, as he acknowledged, abrasive--that left few people with equivocal feelings about him. Even if he had had to worry about being reelected, which he did not, there is little reason to think he would have altered his style.

It says something about Mr. Rosenthal that he struggled for more than a decade to establish a federal agency to represent consumers in court, becoming nationally known as a consumer champion, but ended up not with a new agency but with a marathon educational campaign. The hearings he conducted in his Government Operations subcommittee on commerce, consumer and monetary affairs sharpened his reputation for being that rare legislator on the front line of the public interest.

With many other members of his congressional class, Rep. Rosenthal moved easily to the large causes of the 1960s--the Great Society and, early on, the movement against American involvement in the Vietnam War. A member of the Foreign Affairs Committee, he promoted a stronger congressional role in foreign policy-making while that issue was popular on the Hill, and while it was not. He qualified as a leader of the "Israeli lobby" in the House and, in one disastrous episode involving Cyprus, he threw his weight to the "Greek lobby" as well. Then as always, he fought hard and fairly and without consideration of personal risk or gain.