The Sunni-Shi’a split originated from political succession struggle, not theology.

Evidence

Shi ite and Sunni Muslims share the same basic beliefs in the unity of God, the apostolate of Muhammad, the finality and perfection of the Qur’anic reve­ lation, and the principles and obligations of the holy law. Apart from the crucial issue of the imamate, there are no major theological differences between them, and only relatively minor differences of ritual and law—though the latter, in such social matters as marriage and inheritance, may at times acquire a dispro­ portionate significance. There is thus no meaning to the parallels that are some­ times drawn between the Sunni-Shi a cleavage in Islam and the schisms and heresies that have riven the world of Christendom. The original difference in Islam was political, concerning candidates for office. But in the course of the centuries, as the two main groups grew apart, other differences arose, the most important of which were psychological and emotional—the differences of mood and direction resulting from their greatly different experience. This is true not only of the differences between Sunni and Shi ite Muslims, but also of the many disagreements that arose among the Shi a themselves, dividing them into in­ numerable schools and sects. Here too the differences were in origin political— about which of several claimants was the rightful imam, the rightful head of Shi ite and ultimately of all Islam. And here again, in the course of time, other differences—in belief and practice, in tactics and strategy—were added. — Bernard Lewis, From Babel to Dragomans, 1452 (#corroborates, via linked claim)

At a very early date the famous split occurred between the Sunni and the Shi‘ite views, the Shi‘a doctrine being frankly dynastic. According to them, only the lineal descendants of the Prophet are entitled to rule as his successors. Since the Prophet had no descendants in the male line, a unique exception is made in favor of the descendants of his daughter, Fatima. The Sunni view, in contrast, as formerly set forth, was that the caliphate should be elective. This should not be understood in modern terms of universal suffrage. The juristic concept of election means that on the death of the caliph the most suitable successor is chosen by a small college of qualified electors. — Bernard Lewis, From Babel to Dragomans, 538 (#expands, via linked claim)

Their rise, efflorescence, and decline illustrate another characteristic aspect of Shi ite history—the recurring tendency to split into rival and sometimes con­ flicting groups. In these conflicts among the Shi a, as in the larger dispute between the Shi a and the Sunni Muslims, the original issue was a political one—the question of leadership. All the Shi a were at one in rejecting the Sunni caliph, but they often differed among themselves over his replacement. — Bernard Lewis, From Babel to Dragomans, 1443 (#expands, via linked claim)

Categorization

• XREF: connects to: The Sunni-Shi’a split originated from political succession struggles — Deepa Kumar, Islamophobia and the Politics of…, 317; The Sunni-Shia split is political in origin, not theological. — Bernard Lewis, From Babel to Dragomans: Interpreting…, 1452; The Sunni-Shia split is fundamentally about dynastic versus elective succession — Bernard Lewis, From Babel to Dragomans: Interpreting…, 538 (+2 more)

Broader Connections

• The Sunni-Shia split is political in origin, not theological. #corroborates (1.00) — Bernard Lewis, From Babel to Dragomans, 1452
• The Sunni-Shia split is fundamentally about dynastic versus elective succession #expands (0.92) — Bernard Lewis, From Babel to Dragomans, 538
• Shia schisms repeat because of contested political succession #expands (0.85) — Bernard Lewis, From Babel to Dragomans, 1443
• Vernacular religion, not institutional belief, drives post-conflict sectarian division. #qualifies (0.70) — Nadim N. Rouhana and Nadera Shalhoub-Kevorkian, When Politics Are Sacralized, 2302