Throughout his academic career, a recurring interest for Broszat, like many German historians of the "Hitler Youth generation", was the question of why and how National Socialism occurred in Germany Broszat wrote his dissertation on anti-Semitism in Germany during the Second Reich. As a historian, Broszat was most interested in exploring historical occurrences and the actions of individuals by scrutinizing the broader social structure that underlay the events of the past. In his 1960 book Der Nationalsozialismus (translated into English in 1966 as German National Socialism 1919-1945), Broszat examined Nazi ideology, which he regarded as incoherent. For Broszat, the constants were anti-communism, anti-semitism and the perceived need for Lebensraum. In Broszat's view, these were a cloak for the essence of National Socialism, irrational emotions: an intense desire to realize the "rebirth" of "the German nation"; the need to "act" and irrational hatred directed against those considered Volksfeinde (enemies of the German People) and Volksfremde (those foreign to the German "race"). Broszat saw the primary supporters of the Nazis being the middle classes, who turned to Nazism to alleviate their anxieties about impoverishment and "proletarianization" in the wake of hyperinflation in the early 1920s and the mass unemployment that began with the Great Depression at the end of the decade.

From the mid-1950s, Broszat served as one of the co-editors of the DTV Weltgeschichte journal. Initially, Broszat's work focused on German Ostpolitik (Eastern Policy) in the 19th and 20th centuries and of the muddled socialism of the Nazis. Broszat's work on German-Polish relations in the 19th—20th centuries was to ultimately win him accolades in Poland as one of the first German historians to offer an honest account of German—Polish relations.

In 1962, Broszat wrote a letter to the Die Zeit newspaper to "hammer home, once more, the persistently ignored or denied difference between concentration and extermination camps". In his letter, Broszat claimed this was not an "admission" that there was no Holocaust but rather an attempt to "set the record straight" about the differences between concentration and death camps. Broszat noted the differences between concentration camps, which were places where the inmates were consistently mistreated but were not the subject of annihilation and death camps, which existed to exterminate people. Broszat denied there was a functioning gas chamber at the Dachau concentration camp (though he noted that one was built shortly before the end of the war as part of the effort to convert Dachau into a death camp but was never used). Broszat commented that though there were many concentration camps in Germany, all of the German death camps for the genocide of the European Jews were in Poland. Broszat argued that this confusion in the public's mind between concentration and death camps and the tendency to erroneously describe Dachau as a death camp was aiding the early Holocaust deniers like Paul Rassinier, Harry Elmer Barnes and David Hoggan, who were making much of the fact that there was no functioning gas chamber at Dachau.

In 1963, when the Polish-Jewish historian Joseph Wulf accused the prominent German doctor Dr Wilhelm Hagen, who served in the health department of the General Government during the war, of helping to liquidate Jews living in the Warsaw Ghetto, Broszat together with other experts from the Institute of Contemporary History were involved in the effort to silence Wulf. Hagen, who was a senior official in the West German Ministry of Health falsely claimed to have been opposed to the Holocaust and to have done everything in his power to save the Jews of the Warsaw Ghetto and asked the Institute to support his version of events... Broszat wrote a letter to Wulf demanding that he retract his allegations against Hagen “in the interest of the tidiness of the historical document”

At the 1963—1965 Auschwitz Trial in Frankfurt, Broszat together with other experts from the Institute of Contemporary History such as Helmut Krausnick, Hans-Adolf Jacobsen and Hans Buchheim served as expert witnesses for the prosecution. The report that they complied for the prosecution served as the basis for their 1968 book Anatomy of the SS State, the first comprehensive study of the SS based on SS records. In 1983, Broszat together with the other experts from Institute for Contemporary History played a prominent role in debunking the Hitler Diaries.

Broszat argued against characterizing Nazi Germany as a totalitarian regime and criticized Karl Dietrich Bracher and Ernst Nolte for advancing such a notion. With Hans Mommsen, Broszat developed a "structuralist" interpretation of Nazi Germany. Broszat saw Nazi Germany as a welter of competing institutions, putting forth the thesis that this internal rivalry, not Adolf Hitler, provided the driving force behind Nazi Germany. Hitler in Broszat's controversial view, was (to use Mommsen's phrase), a "weak dictator"; as such the Third Reich was not a monocracy (rule by one man), rather a polycracy (rule by many).

In his 1969 book Der Staat Hitlers (The Hitler State), Broszat argued that Nazi Germany was dominated by a power struggle by various institutions and that these power struggles explained the course that the Third Reich took. Broszat pointed out that the Nazi State was dualistic; the normal institutions of the German state, (theoretically Nazified) operating in parallel to institutions of the Nazi Party, a rival power structure. Broszat was able to prove that beneath the public veneer of Nazi unity, there were endless power struggles between the revolutionary institutions of the Nazi Party and the organs of the traditional German state. In Broszat's view, these power struggles formed the dynamics and structures of the Nazi state, which were the driving forces behind Nazism. Broszat argued these power struggles were a Darwinian competition in which the "fittest" were the most radical elements of the Nazi movement, leading to "cumulative radicalization", to use another of Mommsen's phrases describing the Nazi state. Broszat rejected the view that Hitler was following a "divide and rule" strategy as argued by Bracher and instead argued that Hitler was unwilling and unable to provide for orderly government. Broszat argued that Hitler allowed the Nazi state to become a collection of rival power blocs, which allowed for the release of extremely destructive forces into German society.

That the Nazi state was a jumble of competing bureaucracies in perpetual power struggles, has been widely accepted by historians. The second element, that Hitler was a "weak dictator" is less influential on the grounds that although Hitler did not involve himself much in daily administration, this apparent neglect stemmed not from an inability to do so (as Broszat suggested) but a lack of interest in the quotidian.

Broszat was a Functionalist on the origins of the Holocaust. Broszat argued that the Nazis wanted to have "revolution in society" but because they needed the co-operation of the traditional elites in business, the military and the civil service, they turned their energy and hatred on those groups such as Jews, Gypsies, homosexuals and the mentally ill that the traditional elites did not care about. These groups were subjected to increasing persecution in the 1930s, beginning with internment in concentration camps (which were not initially death camps) and the "euthanasia" program (murder) of people with learning difficulties, escalating into the genocide of Jews in 1941—1942. Broszat argued that aggression abroad was part of the same process of lashing out against Volksfeinde and Volksfremde caused by the Nazi failure to achieve the sort of comprehensive revolution they sought in German society. After all, Hitler had frequently spoken of nationalizing not industry (as conventional socialists wanted) but the people.

In Broszat's view, the evidence was lacking for the thesis that Hitler was executing a "Programme" in foreign policy. Broszat argued that Hitler's foreign policy was motivated his need to maintain his image, which led to efforts to negate any form of restraint imposed by treaties or alliances. For Broszat, the idea of Lebensraum was more of a vague utopian "metaphor" which served to provide a vision for the Nazi movement and was not a coherent foreign policy. Broszat contended that prior to 1939, Hitler's lack of clear policy towards Poland proved that there could have no "Programme" in foreign policy, since Poland's geographical status as the land between Germany and the Soviet Union should have provided for a clear-cut Polish policy. In a 1970 article, Broszat wrote that Operation Barbarossa was not “a calculated plan to realize his [Hitler's] Lebensraum ideas but that he felt compelled to get out from waiting in the summer of 1940 and proceed to a decisive ending of the war”.

In an article first published in the Vierteljahrshefte für Zeitgeschichte journal in 1977, later translated into English as "Hitler and the Genesis of the ‘Final Solution’: An Assessment of David Irving’s Theses", Broszat criticized David Irving's argument in his book Hitler's War that Hitler was unaware of the Holocaust but did accept Irving's argument that there was no written order from Hitler for the "Final Solution to the Jewish Question". Broszat’s essay was notable as the first account of the origins of the Holocaust by a respected historian in which responsibility for the genocide was not assigned entirely to Hitler. Through Broszat took considerable pains to emphasize what he considered the unpleasant aspects of Hitler’s character, writing at one point of Hitler’s “totally irresponsible, self-deceiving, destructive and evilly misanthropic egocentricity and his lunatic fanaticism”, in Broszat’s opinion the Holocaust could not be explained solely with reference to Hitler or his ideas.

Broszat argued that the radical Anti-Semitism of the Nazis had led them to embark on increasingly extreme attempts to expel the Jews of Europe, and after the failure of successive deportation schemes the lower officials of the Nazi state had started exterminating people on their own initiative. Broszat argued that the Holocaust began “bit by bit” as German officials stumbled into genocide Broszat argued that Hitler provided the goal to the functionaries of the German state “to get rid of the Jews and above all to make the territory of the Reich judenfrei, i.e. clear of the Jews” without providing any guidelines as to how this was to be done German officials began a massive program of ethnic cleansing and mass expulsions in Poland and elsewhere without “clear aimswith respect to the subsequent fate of the deportees” Following the abandonment of the Madagascar Plan, after June 1941 German officials hoped that “the spaces to be occupied in the Soviet Union wouldoffer a possibility for getting rid of the Jews of Germany and of the allied and occupied countries” Broszat maintained that when faced with the stalemate on the Eastern Front, the overwhelming of the European rail system by successive deportations and the self-imposed "problem" of three million Polish Jews the Germans had forced into ghettoes between 1939 and 1941, local German officials in Poland started in the fall of 1941 "improvised" killing schemes as the "simplest" solution to the "Jewish Question". In Broszat's opinion, Hitler subsequently approved of the measures initiated by the lower officials and allowed the expansion of the Holocaust from Eastern Europe to all of Europe. In this way, Broszat argued that the Shoah was not begun in response to an order, written or unwritten from Hitler but was rather “a way out of the blind alley into which the Nazis had manoeuvred themselves”. Broszat argued that the Holocaust was not the result of a master-plan of Hitler’s going back to when he wrote Mein Kampf in 1924 but rather was the work of hundreds of thousands of German officials, many of whom were non-Nazis and most of whom were quite ordinary.

In the same essay, Broszat was extremely critical of Irving's handling of sources, accusing him of repeatedly seeking to distort the historical record in Hitler's favor. Broszat wrote with regards to Hitler's War that:

"He [Irving] is too eager to accept authenticity for objectivity, is overly hasty in interpreting superficial diagnoses and often seems insufficiently interested in complex historical interconnections and in structural problems that transcend the mere recording of historical facts, but are essential for their evaluation".

Broszat argued that in writing Hitler's War, Irving was too concerned with the "antechamber aspects" of Hitler's headquarters and accused Irving of distorting facts in Hitler's favor. Broszat complained that Irving was focused too much on military events at the expense of the broader political context of the war and that he had offered false interpretations such as accepting at face value the Nazi claim that the Action T4 "euthanasia" program began in September 1939 to make hospital spaces for wounded German soldiers, when it began in January 1939. Broszat criticized Irving's claim that because of one telephone note written by Himmler stating "No liquidation" in regards to a train convoy of German Jews passing through Berlin to Riga (whom the SS intended to have all shot upon arrival) on 30 November 1941 that this proved that Hitler did not want to see the Holocaust happen. Broszat argued that this was not proof that Hitler had given an order to Himmler to stop the killings of Jews but rather that the comment "No liquidation" referred to that train and was likely to relate to concerns about questions American reporters were asking about the fate of German Jews being sent to Eastern Europe. Broszat questioned whether Hitler had given Himmler any order to save the lives of the people abroad the train, given that the phone call Himmler made from the Wolfsschanze to Heydrich in Prague took place at about 11:30 A.M. and the records show that Hitler did not get up until about 2:00 P.M on November 30, 1941. Broszat criticized Irving for accepting the "fantastic" claims of the SS Obergruppenführer Karl Wolff, that he did not know about the Holocaust (Irving's argument was that if Wolff did not know about the Holocaust, how could Hitler?), despite the fact that Wolff was convicted of war crimes in 1963 on the basis of documentary evidence implicating him in the Holocaust. Broszat accused Irving of seeking to generate a highly misleading impression of a conference between Hitler and the Hungarian Regent, Admiral Miklós Horthy, in April 1943 by re-arranging the words to make Hitler appear less brutally anti-Semitic than the original notes showed. Broszat maintained that the picture of World War Two drawn by Irving was done in a such way to engage in moral equivalence between the actions of the Axis and Allied states, leading to Hitler's "fanatical, destructive will to annihilate" being downgraded to being "...no longer an exceptional phenomenon". The criticism by Broszat was considered to be especially damaging to Irving because Broszat had based his critique largely on the examination of the primary sources Irving had used for Hitler's War.

Broszat was a pioneer of Alltagsgeschichte (history of everyday life). To pursue this aim better he led the "Bavaria Project" between 1977 and 1983, which was intended be a comprehensive look at Alltagsgeschichte in Bavaria between 1933 and 1945. In Bayern in der NS-Zeit ("Bavaria in the National Socialist Era") as the six volumes which were comprised by the "Bavaria Project" edited by Broszat were entitled, he depicted actions such as refusal to give the Nazi salute or regularly attending church as a type of resistance. The emphasis upon resistance in "everyday life" in the "Bavaria Project" portrayed Widerstand (resistance) not as a contrast between black and white but rather shades of grey, noting that people who often refused to behave as the Nazi regime wanted in one area often conformed in others; as an example the Bavarian peasants who did business with Jewish cattle dealers in the 1930s despite the efforts of the Nazi regime to stop these transactions otherwise often expressed approval of the anti-Semitic laws.

Through his work on the "Bavaria Project", Broszat formed the concept of Resistenz (immunity), which is not to be confused with resistance (in German Widerstand). Resistenz referred to the ability of institutions such as the Wehrmacht, the Roman Catholic Church and the bureaucracy to enjoy "immunity" from the Nazi claims to total power and to function according to their traditional values, without seeking to challenge the Nazi regime's political monopoly. Broszat used the Resistenz concept to advance the view that at the local level, there was much continuity in Germany between the Weimar Era and the Nazi era. Broszat argued that there were two approaches to the Widerstand question, namely the "behavioral" approach that focused on intent and the "functional" approach that focused on the effect (Wirkung) on one's actions. For Broszat, the concept of Resistenz was meant to explain how much of the German population was able to evade the Nazi "claim to total power" without seeking to fundamentally challenge the regime. The Resistenz concept proved to be controversial, with Swiss historian Walter Hofer stating:

"The concept of Resistenz leads to a levelling down of fundamental resistance against the system on one hand and actions criticizing more or less accidental, superficial manifestations on the other: the tyrannicide appears on the same plane as the illegal cattle-slaughterer".

Hofer maintained that it was intent not effect that should provide the basis of judging resistance and opposition in Nazi Germany, that the things Broszat included under Resistenz were relatively unimportant and had no effect in the broader scheme of things on the Nazi regime's ability to achieve its goals. Klaus-Jürgen Müller argued that the term Widerstand should apply only to those having a "will to overcome the system" and that Broszat's Resistenz concept did too much to muddy the waters between by speaking of societal "immunity" to the regime. A more sympathetic appraisal of the Resistenz concept came from Manfred Messerschmidt and Heinz Boberach who argued that Widerstand should be defined from the viewpoint of the Nazi state and any activity that was contrary to the regime's wishes such as listening to jazz music should be considered as a form of Widerstand.

During the Historikerstreit of 1986-1988, Broszat again strongly criticized Nolte's views and work. In a 1986 essay entitled "Where the Roads Part" in Die Zeit on October 3, 1986, Broszat called Nolte an obnoxious crank and attacked him for his "offensive" claims that the Holocaust had in someway been forced on the Nazi regime by fear of the Soviet Union As a socialist, Broszat argued against attempts to promote a "less extreme" view of the Nazi period. Broszat argued during the Historikerstreit that Andreas Hillgruber had come close to being a Nazi apologist and that Nolte was one. Regarding Nolte's claim that Chaim Weizmann on behalf of world Jewry had declared war on Germany in 1939, Broszat wrote Weizmann's letter to Neville Chamberlain promising the support of the Jewish Agency in World War II was not a "declaration of war" nor did Weizmann have the legal power to declare war on anyone Broszat commented "These facts may be overlooked by a right-wing publicist with a dubious educational background but not by the college professor Ernst Nolte" Broszat accused Michael Stürmer of attempting to create an "ersatz religion" in German history that Broszat argued was more appropriate for the pre-modern era then 1986 Broszat wrote that "Here the roads part" and argued that no self-respecting historian could associate himself with the effort to "drive the shame out of the Germans". Broszat ended his essay with the remark that such "perversions" of German history must be resisted in order to ensure the German people a better future.

He was best known for arguing in a 1985 essay "A Plea For the Historicization of National Socialism" that Nazi Germany should be treated as a "normal" period of history. His call for "historicization" of the treatment of Nazi Germany was controversial, as Broszat called for historians to cease judging the period in overtly moralistic tones and to embark instead upon scientific, dispassionate analysis as they would for any other time. For Broszat, because historians did not treat the Nazi period the same way other periods were treated, this distance between the historian and his/her subject in regards to the Nazi era led to the Nazi period being treated as "island" of "abnormality". Broszat argued that the Nazi period was a chapter of German history and historians needed to stop treating the Nazi times as one of utter evil with no connection to what came before and after in German history. In Broszat's opinion, the "insulation" that severed the Nazi period from the rest of German history had to be ended

Broszat called the "normalization" of the Nazi era by focusing on Alltagsgeschichte approach that allow shades of gray by examining both the "normality" of "everyday life" and the "barbarity" of the regime. As part of this "normalization", Broszat called for the end of the teleological approach that saw Auschwitz as the culmination of the Nazi regime and instead paid heed to the fact that for most Germans the Holocaust was of marginal concern during the Nazi era and that Auschwitz did not obtain its iconic status as the supreme symbol of evil and inhumanity until after 1945. Broszat urged that historians stop the black and white treatment between "evil" Nazis and "good" anti-Nazis in German society and instead used the more "realistic" approach of noting the shades of grey within German society. As an example of “shades of grey”, Broszat noted that the man designated to serve as Germany’s new chancellor if the July 20 Plot had succeeded, Carl Friedrich Goerdeler was an anti-Semite. Broszat noted that the simplistic contrast between totally “good” anti-Nazis vs. completely “evil” Nazis led to historians ignoring Goerdeler’s anti-Semitism to keep the camps of good and evil pure. Broszat called for a history that could allow one take in account nuances and degrees of agreement between German anti-Nazis and Nazis, thus allowing historians to write a history that could allow one to accept the fact that one could be both an anti-Nazi and an antisemite.

Broszat called for the Third Reich to be integrated into the broad stream of German history and called for a long-range view of the German past with the Nazi era seen as a stage of the broader story of German history rather than being treated as an abnormal period that was not connected to what came before or after. Broszat wrote that "not all those historically significant developments which occurred in Germany during the Nazi period merely served the regime's goals of inhuman and dictatorial domination" and called for a broader look at the Nazi era. Broszat used as an example of his approach, the "Ley Plan" as the wide-ranging reform of the German social insurance system proposed in 1940 by the DAF was known, which Broszat noted borne many striking similarities to the British Beveridge Plan of 1943 (through the German plan applied only to those classified as "Aryans") Broszat argued that such a comparative approach would place the Nazi era in a better broader European and German context, especially since Broszat argued that the German plan of 1940 was in many ways the forerunner of the West German social insurance plan of 1957 with such features as pensions guaranteed by the state indexed to the level of GNP (which was not surprising given that many of the same people worked on both plans) Broszat called for the "normalization" of the historical understanding of the Nazi era with detailed scholarship employing "mid-range" concepts based upon empirical research and rejecting the moralistic condemnation of the period. Based upon his work in Alltagsgeschichte, Broszat felt that particular attention should be paid to the "normality" for most people of everyday life in Nazi Germany and how this "normality" co-existed with the "barbarity" of the Nazi regime. Broszat' call for "historicization" was much influenced by his work in the field of Alltagsgeschichte and by his functionlist understanding of the Nazi period In response to Broszat’s call for the "historization" of National Socialism, the historian Rainer Zitelmann suggested that Broszat’s "historization" approach was a fruitful arguing that just as not everything was evil in the Soviet Union, not everything was evil about Nazi Germany and that the Nazi regime accomplished many successful social reforms

The American historian Gavriel D. Rosenfeld wrote about Broszat's call for "historization" that:

"In the 1980s, the German historian Martin Broszat famously argued that overtly moral analyses of the Third Reich suffered from their embrace of a "black-and-white" perspective that drew too rigid a dichotomy between perpetrators and victims, obscured the era's gray complexity, bracketed off the Third Reich from "normal" modes of historical analysis (such as an empathetic perspective towards the historical actors themselves) and prevented it from being integrated into the large sweep of German history... At the same time, an overly moralistic view runs the risk of mythologizing history and transforming it into a collection of moral ethical lessons that, over time, can easily become stale and cease to resonate within society at large. It was for this reason that German historian Martin Broszat in the 1980s called on German to "historicize" the Nazi era by abandoning their simplistic black-and-white image of the Third Reich as a story of demonic villians and virtuous heroes and replacing it with a grayer perspective that recognized the period's immense complexity."

Broszat's call for the "historicization" of the Third Reich as opposed to the “demonization” of the period, involved him in a vigorous debate with three Israeli historians in the latter half of the 1980s. The three historians Broszat debated were Otto Dov Kulka, Dan Diner and above all with the Franco-Israeli historian Saul Friedländer. During an exchange of letters with Broszat during the late 1980s, Friedländer argued that there were three dilemmas and three problems involved in the "historicization" of the Third Reich. The first dilemma was that of historical periodization and how long-term social changes could be related to an understanding of the Nazi period. Friedländer argued that focusing on long-term social changes such as the growth of the welfare state from the Imperial to Weimar to the Nazi periods to the present as Broszat suggested changed the focus on historical research from the particular of the Nazi era to the general longue durée (long duration) of 20th century German history. Friedländer felt that "relative relevance" of the growth of the welfare state under the Third Reich and its relationship to post-war developments would cause historians to lose attention of the genocidal politics of the Nazi state. The second dilemma Friedländer felt that by treating the Nazi period as a "normal" period of history and by examining the aspects of "normality" might run the danger of causing historians to lose interest in the "criminality" of the Nazi era. This was a cencern for Friedländer because he contended that aspects of "normality" and "criminality" very much overlapped in the everyday life of Nazi Germany. The third dilemma involved was Friedländer considered the vague definition of "historicization" entailed and might allow historians to advance apologetic arguments about National Socialism such as those Friedländer accused Ernst Nolte and Andreas Hillgruber of making. Friedländer conceded that Broszat was not an apologist for Nazi Germany like Nolte and Hillgruber. Friedländer noted that through the concept of "historicization" was highly awkward one because it opened the door to the type of arguments that Nolte and Hillgruber advanced during the Historikerstreit, Broszat's motives in calling for the "historicization" were honourable.

The first problem for Friedländer was that the Nazi era was too recent in popular memory for historians to deal with it as a "normal" period as for example 16th century France. The second problem was "differential relevance" of "historicization". Friedländer argued that the study of the Nazi period was "global", that it belongs to everyone and that by focusing on everyday life was a particular interest for German historians. Friedländer asserted that for non-Germans, the history of Nazi ideology in practice especially in regards to war and genocide were vastly more important then Alltagsgeschichte. The third problem for Friedländer was that the Nazi period was unique so that it could not easily fit into the long-range view of German history as advocated by Broszat. Friedländer maintained that the essence of National Socialism was that it "tried to determine who should and should not inhabit the world" and the genocidal politics of the Nazi regime resisted any attempt to integrate it as part of the "normal" development of the modern world. The debate between Broszat and Friedländer were conducted through a series of letters between 1987 until Broszat's death in 1989. In 1990, the Broszat-Friedländer correspondence were translated into English and published in Reworking the Past Hitler, The Holocaust and the Historians' Debate edited by Peter Baldwin.

In a letter of September 28, 1987, Broszat conceded to Friedländer that the "historicization" concept was open to abuse but argued that the concept was needed as the Nazi period had to be subject to rational historical analysis and was needed to provide a sensible way of understanding the Nazi era In response, Friedländer wrote that he did not feel that there was a "blockade" severing the Nazi period from the rest of German history, used Hillgruber's essay in his 1986 book Zweierlei Untergang calling for historians to sympathize with German troops fighting on the Eastern Front in 1944-45 as an example of the abuse of "historicization" and described Broszat's condemnation on a "moralistic" history written that assigned a leading role to the "victims" of National Socialism as a very troubling In a letter of October 26, 1987, Broszat wrote he was concerned that because of the iconic status of Auschwitz too much history was being written backwards with historians starting with Auschwitz and treating everything in the Third Reich as an long countdown to genocide

An even more harsher assessement of Broszat’s "historicization" concept than Friedländer's came from the Israeli historian Omer Bartov, who accused Broszat of being a German apologist and of seeking to diminish Jewish suffering in the Holocaust, indeed the Holocaust as a study in history because as a German historian he was not comfortable with dealing with Germans as perpetrators of genocide and Jews as victims of German genocide On the other side, the American historian John Lukacs wrote that Broszat's call for "historicization" was long overdue and was most necessary The German philosopher Jürgen Habermas wrote that Broszat had written "convincingly" on the need for "historicization" Hans Mommsen praised Broszat's call for "historicization" as a way to avoid "...this ubiquitous tendency to "shake off the mortages of a past now happily made morally neutral"". The British historian Richard J. Evans praised Broszat's “historicization” concept as offering a “rational” way of understanding the German past and as a “gain” to history

Broszat saw his work as kritische Aufklärungsarbeit ("critical enlightenment work") and criticized his colleagues for adopting what he perceived as an ahistorical, moralistic approach to history. Broszat's motto was "Geschichte ist nicht Wissen, sondern Leben" (History is not knowledge, but experience"). Broszat often attacked historians such as Klaus Hildebrand, Andreas Hillgruber and Eberhard Jäckel for concentrating upon Hitler and his beliefs as explanations for Nazi actions. Broszat saw professional history as a social science that should examine society and culture rather than an individual in explaining the past. Though in disagreement with some of Broszat's conclusions, the British historian Sir Ian Kershaw is Broszat's leading disciple.