After Muhammad's death, the sunni wanted Abu Baker, Muhammad's closest advisor, to become the new leader of the muslim world, while the Shi'a favored Muhammad's cousin Ali. Abu Baker was made the leader of islam, but this left many bitter feelings and more disagreements arose between the two sides, especially many years later following Ali's assassination, eventually leading to the creation of two separate sects.
An innovative way was an improvised vaccination.
This consisted of smearing open cuts of healthy people with substances taken from wounds of sick people (for example sick from smallpox) in the hope that they will undergo a mild version of the disease and when the disease catches them, not die.
The risk was that they could get seriously ill, but the advantage was that on average, they had better survival chances than without this "vaccine"
Answer:
more equality for women and minority groups is the answer
Common sense was what shifted the grievances.