The Man Who Organized the Holocaust : HIMMLER, <i> By Peter Padfield (Henry Holt: $39.95; 656 pp.)</i> : THE ARCHITECT OF GENOCIDE; Himmler and the Final Solution, <i> By Richard Breitman (Alfred A. Knopf: $23; 315 pp.)</i>

Of all the neurotic conspirators who surrounded Adolf Hitler, none was more utterly weird than Heinrich Himmler, the unsmiling Reichsfuhrer-SS , organizer and commander of the German police, the concentration camps, and the Holocaust.

The son of a schoolteacher, who himself looked like a schoolteacher and spoke like a schoolteacher, he was, second only to Hitler, the most powerful man in the Third Reich and probably the most thoroughly evil. He not only created the hell of Auschwitz but went there several times to inspect its operations.

One day in 1943, according to the testimony of an Auschwitz prisoner named Rudolf Vrba, one of the gas chambers was packed with prisoners by 8:45 so that Himmler could watch a mass killing at 9. But Himmler dawdled over breakfast, so the increasingly frantic prisoners had to wait inside the chamber until the Reichsfuhrer-SS arrived at 11, took his position at the peephole and observed the gassing. “What he had seen seemed to have satisfied him and put him in good humor,” Vrba recalled. “He accepted a cigarette from an officer, and . . . laughed and joked.”

Passionately devoted to Hitler, to the Nazi theories of Nordic racial supremacy and to the 18-hour day, Himmler tirelessly expanded his power until he controlled not only the private empire of the SS, with all its prisoner-operated factories and mines, but also the battlefields where his Waffen - SS armored divisions fought ferociously against the Allies.

Yet even at the height of his power, Himmler spent time organizing an archeological mission to Tibet to search for primeval Aryan artifacts. Early in 1941, about halfway between the Germans’ conquest of France and their invasion of the Soviet Union, Himmler discussed at length with Hitler his plans for a Women’s Academy of Wisdom and Culture, where a selection of blue-eyed blonds would be trained in history, foreign languages, chess and fencing, then given a diploma as “Chosen Women,” eligible for marriage to leading SS officers.

If Himmler was not aware of his weirdness, others were. One Gauleiter narrowly escaped with his life after having said of the flabby and bespectacled SS leader: “If I looked like Himmler I would not talk about race.” Himmler’s body extorted its own price: He suffered all his life from excruciating headaches and stomach cramps. Nothing could help him except the ministrations of a Finnish masseur named Felix Kersten, who recalled once finding him twisted in agony. “Please help me,” begged the overlord of Auschwitz. “I can’t bear any more pain.”

This is, as the old phrase goes, a story that you couldn’t kill with a stick. Padfield, a Briton who has written a number of naval histories, ranges far, and in splashy detail, over both Himmler’s crimes and his little domesticities, his affair with his dutiful secretary, and the two illegitimate children that he installed in a villa at the expense of the Nazi Party.

Padfield’s publishers proclaim that this is “the first full-length biography” of Himmler, but this is not true; it is just the longest. Willi Frischauser, for example, wrote one back in 1953; Roger Manvell and Heinrich Fraenkel wrote another in 1965, and Himmler is the dark villain of almost every major work on the Holocaust.

These earlier biographers also sought out and interviewed people who had known the Reichsfuhrer-SS ; Padfield admits that he did not, for “the few whom (sic) I thought might contribute . . . would neither see me nor answer my letters.” He hastens to add that “This is not as serious as it might appear because so many evasions and downright lies have circulated that it has become impossible to separate fact from fiction in any recollections of participants.”

So this is a very readable but somewhat flawed book. One basic flaw is that Padfield has tried to include in his sprawling work the whole history of the Third Reich. This makes him take his readers through such familiar scenes as the invasion of Poland and the Battle of the Bulge, accompanied by useless comments such as “Himmler appears to have played little part in the decisions of these fateful days” and “Strangely, Himmler was missing from this.”

A more symptomatic flaw is that Padfield seems obsessed with the Nazis’ habit of lying about everything. “There is only the memory of those who overheard him,” he says at one point to disparage eyewitness testimony of what Hitler actually said at a meeting, “and these memories have proved most selective.”

But while Padfield is understandably skeptical about both Nazi testimony and Nazi documents--constantly speculating about what some statement might or might not signify--he also has a penchant for spinning undocumented theories on his own. He suspects, for example, that the “blood purge” of 1934, in which Himmler’s SS cut down the rival Storm Troopers (SA), was actually a clash between two rival factions of big business. He suspects that Rudolf Hess’ mysterious “peace mission” to Britain in 1941 was an SS trick, and that SS agents somehow provoked young Herschel Grynszpan into assassinating a German diplomat in Paris, which became the pretext for Kristallnacht . “No proof was found at the time,” he says, with a characteristic Fleet Street touch, “and probably no proof will ever be found.”

The central mystery, of course, remains the question of how and why Himmler became what he was. Padfield explores the usual possibilities: the horrors of the Catholic Inquisition, the dark side of the German national character, and, of course, the questionable revelations of psychiatry. He quotes approvingly from an investigator named Harry Guntrip: “When an individual is inwardly menaced by an involuntary schizoid flight from reality, he will fight to preserve his ego by taking refuge in internal bad object fantasies of a persecutory or accusatory kind.”

Such theorizing means little enough when the theorizer has his patient on a couch, but long-range psychiatric speculations about Himmler run into the fact that the monster seems to have had quite a happy childhood. His father encouraged his schoolwork; his mother doted on him; there may have been the usual subterranean tensions, but nothing that points the way to Auschwitz.

Like everyone else, Padfield finally confesses himself baffled. “We are peering dimly into a madhouse,” he writes, “but it is a communal asylum, and the inmates go home in the evening and discuss homeopathic medicine or read their children bedtime fairy tales.”

Richard Breitman, a Harvard-trained professor at American University, has a more precise focus and a more restrained approach. Though he includes a succinct biography of Himmler, he states at the beginning that “There is no simple environmental or psychological explanation as to why Himmler became a mass murderer on an unprecedented scale.”

Breitman’s central concern, though, is an almost equally mysterious question: What is the meaning of the fact that nobody ever has found a document in which Hitler ordered Himmler to undertake the Holocaust? The traditional answer is that Hitler must have given the horrifying order orally and secretly, but that he had openly proclaimed such an intention as early as “Mein Kampf” (1925). Some historians recently have argued, however, that the Holocaust may have been more or less improvised by various lower officials under the pressure of the war. “A planned Final Solution and an improvised one carry quite different moral and philosophical implications,” Breitman writes.

True enough, but these are not equally valid theories. As Breitman persuasively demonstrates, the situation kept changing, but Hitler was always in charge, and his goals always included ridding his empire of the Jews. The only questions were when and how.

There actually weren’t very many Jews in pre-war Germany--less than 1% of the population--but Hitler started by harassing them and trying to expel them. Other countries, notably the United States, refused to accept large numbers of refugees. Then there was talk, which Breitman takes more seriously than most, of deporting the Jews to Madagascar, or somewhere.

The outbreak of war in 1939 changed everything, suddenly increasing the number of Jews under Nazi rule by some 3 million. Himmler’s Einsatzkommandos began shooting them down in large numbers, but that was too disorganized. Hitler’s master plan was to resettle millions of Germans in the East, and one of the first steps was to confine Poland’s Jews in ghettos.

Nobody knows exactly when that resettlement plan evolved into genocide, but Breitman argues that “by March 1941, the Final Solution was just a matter of time.” Himmler’s deputy, Reinhard Heydrich, announced it to all major branches of the government at the Wannsee Conference of January, 1942, and in August the authorities approved plans for the four great crematoria that could annihilate 10,000 people per day at Auschwitz.

After the fiery collapse of Hitler’s Reich, Himmler wandered around in disguise, with false identity papers and a black patch over one eye. Under interrogation by the British, he removed the patch, put back his spectacles, and quietly said, “Heinrich Himmler.”

Ordered to strip for a search, Himmler waited until the searchers opened his mouth, then bit down on a hidden cyanide pill. The investigators held Himmler’s naked body upside down and tried to pump out his stomach, but the Reichsfuhrer-SS died within 15 minutes.

“Did images of Bavaria flood the timeless moment as the poison stunned his nerve centers?” Padfield characteristically asks.

Breitman, by contrast, quotes a British officer simply saying: “The bastard’s beat us!”