Surak is considered the father of Vulcan logic. He developed his philosophy, which espouses suppressing emotion in favor of using logic to make decisions, during a time on the planet Vulcan when warring factions threatened the extinction of the species. Vulcans consider themselves to be a peaceful race, although they do at times resort to warfare as the need to do so presents itself logically.
Vulcan politics are based in democracy with representatives elected by the people. There also is a group of elders known as the Vulcan High Council which acts as caretaker to the history of the Vulcan people. By the 22nd century, the Vulcan High Command was the most powerful government on the planet, controlling both civilian and military agencies.
According to a "Star Trek: The Next Generation" episode called "Gambit, Part II," Vulcans originally practiced a religion similar to Pagans, worshiping many different gods. The philosophy of suppressing emotion and following a path of pure logic came into being during the fourth century known as the "Time of Awakening," when Vulcan wars threatened to destroy the entire planet. Vulcans, along with humans, Tellarites and Andorians, were instrumental in forming the United Federation of Planets, a governmental body similar to the United Nations.
Romulans originally were a minority group from the planet Vulcan that rejected the philosophy of logic and the suppression of emotion developed by Surak. This faction left the planet to form its own colony during the fourth century and eventually settled on the planets Romulus and Remus, with Romulus acting as the capitol. Since Romulans did not adhere to the Vulcan principles of logic, the species remained aggressive and antagonistic in contrast to their biological cousins.
Many television episodes denote that Romulans are known imperialists, similar to the Klingons, but will form alliances when they are deemed beneficial to Romulan desires. The Romulans employed two main bodies of government, both overseen by the Romulan Senate. The Romulan Star Empire, which ruled the Romulan people and the other species it conquered, was overseen by the Romulan Senate. The Senate functioned as an oligarchy with central governments wielding all authority. Likewise, the Romulan Continuing Committee, which functioned as a criminal court, also was overseen by the Romulan Senate.
Romulans are primarily a military-based culture, so social status largely is determined by a Romulan's military rank and service, as is largely discussed in the "Star Trek: The Next Generation" episode "The Defector." Romulans believe in the celebration of emotion and devout loyalty to their own species and to their government. They also believe the greatest honor bestowed on an individual is to die while in military service. Romulans have a shared belief that their species is superior to any other race, which has led to speculation among "Star Trek" fans that they are a racist species.