Harvey Whitehouse (2018) says that an individual who is fused with his group “equates his personal identity with the identity of the group.” For highly fused individuals, the “boundary between personal and group identity is porous.”

Citing Swann et al. (2009), Whitehouse states that fusion involves a “visceral feeling of oneness with the group” such that essential features of one’s social reality are also “considered to be essential features of one’s personal self.”

Vamik Volkan (1988) writes that the sense of self is often intertwined at a primitive level with the sense of ethnicity:

Membership in these groups is tinged with raw and primitive affects pertaining to one's sense of self. In some circumstances, the individual will destroy others or die himself in order to solder himself to such sentiments.

Perhaps the clearest and most profound case of fusion with the group occurred during the Nazi era, 1933-1945. Hitler’s deputy Rudolph Hess often introduced the Fuehrer at rallies declaring, “Hitler is Germany, just as Germany is Hitler.” This phrase lay at the heart of Nazism.

Hitler equated himself with the national group, and the German people equated themselves with Hitler. Hitler’s aspiration was to cause the German people to fuse together as one—to be melted together—so that there was no separation between individuals and the group.

Hitler expressed his own feeling of “visceral oneness with the group” when he spoke of the “great mass of the decent, industrious German Volk from all tribes and levels” as people he had “taken so much to my heart, whom I love, with whom I feel at one, closely united down to the last fiber.”

Understanding that Germany consisted of diverse tribes and classes of people, Hitler recognized that his job as leader was to bring the German people together as a single, united group. Hitler’s passion and will was directed toward persuading Germans to come together—to fuse with the national group. He explained to the German people:

Our Nation is not just an idea in which you have no part; you yourself support the nation; to it you belong; you cannot separate yourself from it; your life is bound up with the life or your whole people; the nation is not merely the root of your strength, it is the root of your very life.

At the center of Nazism were the mass-rallies, where tens-of-thousands of Germans massed together within a single physical space. The mass-meetings and rallies expressed Hitler’s desire to create the physical experience of fusion, or oneness.

In Mein Kampf (1925), Hitler explained his methodology and its underlying psychology:

The individual who at first feels lonely and easily succumbs to the fear of being alone—for the first time gets the picture of a larger community, which has a strengthening, encouraging effect. But the community of the great demonstration not only strengthens the individual, it also unites and helps to create an esprit de corps.

Man needs that strengthening which lies at the conviction of being a member and fighter in a great comprehensive body. And he obtains an impression of this body for the first time in the mass demonstrations. People came to my speeches as my enemies, but gradually it transpired that after my speech lasting three hours, adherents and adversaries fused into a single enthusiastic mass.

Hitler claims that at the conclusion of one of his speeches, adherents and adversaries both had fused into a single enthusiastic mass . Above all else, Hitler aspired to fuse the German people into a single, united body.

When it comes to the large community, the formation of a “group” is not automatic or self-evident. It is not given, a priori. Hitler understood this—recognized that his job as leader was to bring the German people together.