A social critic nowadays is anybody who can stand up in a nightclub and make jokes about Nancy Reagan.
A cartoonist is anybody who can draw a cat.
No wonder Robert Osborn, who is both a social critic and a cartoonist, prefers to call himself a ''drawer.''
A man who once taught Greek philosophy at Hotchkiss (while also coaching football, track, and skeet shooting), Osborn is a writer too. He has drawn and written a sort of autobiography, ''Osborn on Osborn'' (Ticknor & Fields, $29.95 ).
Jules Feiffer, a social critic and cartoonist and drawer and writer just 25 years younger than Osborn, has also just issued a retrospective - ''Feiffer: Jules Feiffer's America from Eisenhower to Reagan'' (Knopf, $25).
This column will be in praise of those double talents who can add sharp words to sharp lines, and vice versa.
People, like Osborn, who started to grow up before World War I are beginning to seem a national treasure. In their later years they draw upon the 19th century, whose shadow hung over their childhood. A certainty of line and word runs through ''Osborn on Osborn'' that few totally 20th-century men could manage without bluster.
The son of an Oshkosh, Wis. lumberman, Osborn can remember his father bringing down his fist on his mahogany dining room table and crying, ''I don't care if everyone in this city believes one way and I believe the other. . . .''
Osborn has become his father. He is almost anachronistically full of convictions. The very purpose of life, and art, he argues, is ''to be clear and aware of who you are and what you believe in.''
There is not a waffling word or a wobbling line in this book. Osborn confesses to ''considerable indignation,'' and it's all there in his eyebrows. When he writes of his ''loves'' (Mozart, model planes, fresh green figs, his wife of four decades, Elodie) and his ''hates'' (above all, ''THE BOMB''), he does not trouble himself with the qualifying phrase. He lets it rip, as in the not uncharacteristic sentence: ''To all this I say, 'Rubbish!' ''
One hears the same authority that one still hears in the voice of Osborn's classmate at Yale, Dwight Macdonald, another ''social critic.''
''Convincing lines'' - Osborn's phrase - mark every illustration in this book , from a sketch of his childhood cook to a portrait of Einstein, from a muskrat in Connecticut, where Osborn has lived for more than 40 years, to a view of Avignon (he also did his time as expatriate).
It would be easy to believe that Osborn has been drawing masterfully since he put his first face on a kite back in Oshkosh. Not so. He went through a long, troubling apprenticeship as a painter before the Navy in World War II assigned him to doing cartoons for training manuals for pilots.
What a perfectly absurd way to find your metier, and how Osborn cherishes it all!
As an illustrator for Harper's, Life, Esquire, Vogue, the New Republic, Osborn has devoted his ''convincing lines'' to all sorts of themes. His cartoon of ''Fear,'' with disembodied hands clutching the throat, seems to capture all the other emotions too, from anger to greed, that try to throttle humanity. But for a social critic, he does a lot of lyrical soaring - a collage of Charlie Chaplins; a lovely sequence of grasshoppers; Mendelssohn's music surrealized as a peacock.
Feiffer acknowledges Osborn as one of his early models. But as social critics , as cartoonists, the two are a generation apart. Feiffer is as much a poet of uncertainty as Woody Allen - a witness, by his own description, to ''alienation'' and ''anxiety,'' ''self-loathing'' and ''self-searching'': every kind of avant-garde ''smugness'' that has ''passed for revolution.'' In two words, Greenwich Village.
Even Feiffer's political cartoons - Kennedy, Johnson, Nixon - are interesting primarily for the New York-intellectual perspective they record.
The drawings are sometimes almost buried in the words that surround them. Everything gets articulated until the soul is tied in knots.
Feiffer, the Dante of Washington Square, looks at his fellow man and says, in effect, ''I shudder.'' Nobody shudders better.
Osborn, the ice skater from Lake Winnebago, finally looks beyond his contemporaries to nature. He gazes with awe and affection at mallard ducks, ''today looking exactly like the ones that march by us in ancient Egyptian murals; in short, at the whole scheme of things, repeating or evolving under their own forces upon this earth.''
His concluding words: ''I marvel.''