WHO WAS the first working-class premier of Italy? Some clues may be helpful. He was a sensitive violin-playing intellectual, an ardent patriot who saved Italy from Red chaos and tyranny, transformed it into a modern industrial country, and gained the admiration of the whole world. In the 1930s he took initiatives to rally Europe against the Nazi menace.

But in the end he found himself driven into an alliance with Adolf Hitler, the one "fatal mistake of his life." He died bravely, victim of a gangland-style roadside assassination ordered in April 1945 by Communist boss Palmiro Togliatti, who feared that if the now-deposed premier fell into the hands of the advancing American troops, he would make "embarrassing disclosures" about the Communist reign of terror in northern Italy.

If you do not recognize this man, another set of clues is available. He was a sullen paranoid bully and pathological liar, who saw ideas only as weapons to be employed or discarded as circumstances required, in a single-minded struggle for political power. He imposed a ruthless dictatorship on a divided nation that failed to understand until too late how dangerous he really was.

Once installed in power, he led Italy from one disaster to another. His regime consisted of little more than thuggery, sham, and bluster. He bears full personal responsibility for the many brutal wars of aggression that Italy fought during his rule, wars that increasingly revealed his thoroughgoing administrative incompetence. At the end, after presiding over a baleful reign of combined Fascist and Nazi terror in northern Italy, he tried to slink into Austria disguised as a Luftwaffe officer but was executed by the 52nd Garibaldi Brigade of Partisans.

The first set of clues is supplied in a new political biography of Benito Mussolini by the American scholar Anthony James Joes. The second set is taken from a new political biography of Mussolini by Denis Mack Smith of Oxford. The two books have little in common except their titles. Joes writes as if he were the lawyer for the defense in a postwar international tribunal. Mack Smith writes as if he were the chief prosecutor. Both men resort to all the tricks of the legal trade: omission of inconvenient evidence, consistently one-sided construction of doubtful sources, misleading quotation of witnesses, and all the rest. The characterizations of Mussolini that emerge from their labors are diametrically opposed, and almost equally unbelievable.

One must say "almost," because Mack Smith is clearly the better scholar. He massively documents his factual statements, citing more than 1,200 sources in twice that many endnotes. Joes cites his sources haphazardly, and uses a more meager assortment. Mack Smith's rhetoric is more restrained. He slants his evidence less outrageously. He shuns Joes' irritating tactic of quoting apparently supportive opinions from scholars who would emphatically reject his view of Mussolini. One of these sorely abused scholars is Denis Mack Smith himself, whose Italy: A Modern History (published in 1969) Joes cites at least six times.

But Joes and Mack Smith both insult the intelligence of their readers by seeing little except the virtuous and the villainous, respectively, in their subject.

Joes' Mussolini, for example, had no responsibility whatever for the death of the Socialist deputy Matteotti in 1924. On the contrary, Matteotti may have been kidnapped by opponents of the Duce's program of national conciliation. In any case, the deputy probably died of a heart attack after nothing worse than a beating. Joes' Mussolini agonized over the affair, suffering the first episode of severe stomach cramps that plagued him all the rest of his life. The viciousness of the Socialist campaign against him left Mussolini with no alternative but to assume dictatorial powers, powers that Joes claims he did not intend to seek, although they were hardly greater than those wielded by many premiers of Italy who had preceded him.

Mack Smith's Mussolini, by contrast, gave orders that prompted one of his chief henchmen to instruct two notorious Fascist hoodlums to kill Matteotti, thus removing the only man with guts enough to oppose his march to absolute power. In various ways the Duce protected all those implicated. He paid hush money for years to a man convicted of the crime, a "professional gangster" and Fascist squad-leader. All of Mack Smith's evidence points to Mussolini's deep complicity in the outrage and in its attempted cover-up. His seizure of dictatorial powers in 1925 followed inexorably.

Which story is true? The Matteotti affair is at least as complex as the Watergate scandal. All the pertinent facts will probalby never come to light, and it is unlikely that anyone now alive knows exactly what happened, or why. But every fact or surmise offered by Joes is intended to advance the case for Mussolini's innocence and every one offered by Mack Smith is intended to advance the case for his guilt.

Another revealing contrast (among hundreds) appears in the treatment by the two authors of the Ethiopian and Greek campaigns. To help minimize Mussolini's shortcomings as a war leader, Joes dwells almost lovingly on the Italian triumphs in Ethiopia in 1935-1936, but spares only one sentence for the pathetic war with Greece in 1940-41. Mack Smith devotes three sentences to the Italian military victory in Ethiopia, but lavishes nine juicy pages on the Greek fiasco. Another case in point, and much more serious: Joes tends to look on the members of Mussolini's Fascist party after 1925 as social workers, whereas for Mack Smith they are virtually indistinguishable from Mafiosi.

This is not to say that Joes and Mack Smith always disagree. Joes repeatedly proclaims and Mack Smith grudgingly concedes that Mussolini was far less inhumane than Hitler or Stalin. They both see Italy's role in World War II as a catastrophe for the Italian people, and assign to Mussolini most of the blame. They both deplore his choice of second-rate sycophants for aides and ministers.

But history is not well served by the fireworks of the law court. Nor have the various earlier biographies of Mussolini served it much better, with the possible exception of the multi-volume study by Renzo De Felice, which is not yet finished and not yet translated. We still have no sober, comprehensive, and scrupulous account in English of the most important Italian of the 20th century. Good biographies of Hitler abound. We must wait a while longer for someone to make sense of Mussolini.