Samuel Morgenstern, a Jewish businessman in Austria, was a loyal buyer of young Adolf Hitler's paintings in Vienna.
Morgenstern probably did not have any idea that the young painter, whose works he was so fond of, would turn into a murderer within the next few years.
Perhaps he did not also realise that Hitler would end up killing six million Jewish people just because he thought them to be "different because of their bloodline".
For any person with minimum sanity, it was hard to imagine what Adolf Hitler did to the Jews on the basis of an imposed "otherness" of bloodline and race. Or how the Pakistani rulers massacred millions of Bangalis in religious pretext in the then East Pakistan in 1971.
In spite of having a blood-spattered lesson from the last century, the world seems to be gradually chipping into the old race of hatred against "other" people based on their race, religion as well as civilisational differences.
On March 15, 2019, Mucad Ibrahim, a 3-year-old child, died in his father's arms after a white supremacist attacked a mosque in Christchurch, New Zealand, killing 51 worshippers.
Or take Nobel laureate Nadia Murad as another example,the Yazidi human rights activist who was "lucky" enough to survive after the IS – avicious terrorist group who killed and raped thousands of people in Iraq and Syria – soldher into sex slavery.
The number of cases such as these, where men, women and children are attacked because they are considered as "different", is increasing around the world. Intolerance against others' opinions and beliefs is breeding hatred among different communities around the world.
These issues are heating up global politics to the extent that alt-right nationalists are gradually sweeping in at the centre of world power allowing the rise of various hate groups like white supremacists, neo-Nazis, and faith-based extremists.
What is otherness? How could this breed a reason for violence?
From a sociological aspect, this idea of otherness has a lot to do with the construction of social identities.
According to American sociologist George Herbert Mead, our outgoing social interaction with other people and our "self-reflection about who we think we are according to these social exchanges" creates social identities.
This is where our brain begins to process the classification of people based on language, colour, race, faith and gender. The French existentialist philosopher Simone de Beauvoir portrays otherness as "a fundamental category of human thoughts."
We find a proper explanation of these "fundamental" human thoughts in Polish sociologist Zygmunt Bauman's book titled "Modernity and Ambivalence" where he wrote, "Woman is the other of man, animal is the other of human, stranger is the other of native, abnormality the other of norm, deviation the other of law-abiding…enemy the other of friend."
Otherness is a basic human thing about social identities as long as collective powers of identities in terms of majority and minority are not contested.
Now, power-playing role of the majority often determines the narratives of the society and representation of various groups breeding the ground for ideas of superiority and inferiority to ensure a cycle of hatred among different communities.
To understand the determinants of social narratives, rising Islamophobia in the west and blasphemy laws in some Muslim countries are perhaps two of the finest examples of how majority determines the narratives of a particular society while reflecting their power muscles and rejecting the "other" ideas.
Why would people hate each other?
The RTI International, an organisation for research and technical services, conducted a research on the former members of various hate groups like white supremacists and neo-Nazis.
It found that around 75 percent of the 47 interviewees were "exposed to racist comments from family members (parents, grandparents, aunts and uncles) as children."
This exposure to hate comments from family members or peer groups breeds hatred in the majority based on a sense of superiority over the minority "other".
On the other hand, for the minority, exposure to hate comments may often breed fear that as a form of defence mechanism turns into hatred for the "majority" other.
Sigmund Freud's "projection" phenomenon –"I am not terrible; you are" – that we reject what we hate about ourselves is also an instance why people hate.
Psychologists often describe fear of others, fear for ourselves, lack of self-compassion, societal and cultural factors as the motivations for hatred. This individual level of hatred gets severe when they are misused in political causes.
The El Paso attacker, 21-year-old white supremacist Patrick Crusius, is one such individual. His personal grudge over the Hispanic population became politicised after his fellow white supremacist Brenton Tarrant perpetrated massacres in Christchurch mosques.
Most of the acts of terrorism and hate crimes around the world could be connected through this dot of estranged individuals' involvement in the broader aspect of hatred.
At what cost?
According to the 2017 FBI report of hate crime statistics, only in the United States, 7,106 single-bias incidents involved 8,493 victims while 69 multiple-bias incidents involved 335 victims.
Each year, hundreds of people lose their lives in white supremacists and neo-Nazi attacks in the West.
On the other hand, in Muslim countries, extremist groups kill thousands of people each year just because of differences of beliefs and opinions.
Hate-based crime is getting the better of many democracies of the world like India for an example where far-right extremist groups are ravaging the lives of the minorities because of religious differences.
In the modern world, we find abundant instances where states are directly involved in the repression of the "other" people; China's Uyghur treatment sets the worst such example.
In a time, when the world is gradually turning to the right, rejection of otherness is further contributing to the rise of a neo-Nazi world order.
Unless the world wakes up and retrieves sanity to embrace otherness as a "fundamental category of human thoughts", stopping the tragic repetition of the last century will be trapped in a question mark.
Nobel laureate Amartya Sen has a say in his book "Identity & Violence": "Civilizational or religious partitioning of the world population yields a 'solitarist' approach to human identity, which sees human beings as members of exactly one group. A solitarist approach can be a good way of misunderstanding nearly everyone in the world."