Sunni and Shiʿi Traditions: The History of Differences and Internal Diversity

“So that you may come to know one another.”

Qurʾan 49:13, excerpt; Dr. Mustafa Khattab’s English translation, The Clear Quran. Editorial English rendering of the approved Russian version, which the article’s author translated from English. The verse concerns peoples and tribes; its application to dialogue between schools here is analytical.

About this article

Two museum labels seem sufficient until a visitor begins reading the names, schools and histories behind them. Sunni and Shiʿi traditions differ, yet each contains diversity that disappears behind a convenient pair of labels. We examine leadership after the Prophet Muhammad’s death, different understandings of authority, Sunni legal schools and several Shiʿi branches. We also discuss Karbala as an event and religious memory, distinguishing history from doctrinal meaning. Particular sources then bring these distinctions into focus: al-Sistani’s normative guidance presents a Twelver Usuli position, while the contemporary Amman Message states a principle of mutual recognition without abolishing disagreements. Christian confessional documents show why shared vocabulary does not guarantee shared foundations. The contemporary scenarios are our own analysis. The aim is to read differences without quietly making one group the norm and another a deviation, or making a person an exhaustive illustration of their affiliation.

I. After the Prophet: Leadership of the Community

The Prophet Muhammad’s death in 632 raised the question of the community’s future leadership. The Harvard Pluralism Project’s brief introduction presents the difference through recognition of Abu Bakr and the position of supporters of Ali, the Prophet’s cousin and son-in-law. This provides an orientation, rather than replacing research into the traditions’ gradual formation.

On an imaginary museum tour, a visitor stops beside two labels: “Sunni” and “Shiʿi.” He immediately asks how the people behind these words differ. One answer lists dates, another rituals, a third reduces everything to conflict. None yet explains what people do when they acknowledge religious authority, preserve memory and belong to a particular community.

Farhad Daftary’s scholarly survey, “Diversity in Islam: Communities of Interpretation”, stresses the gradual development of teachings and the difficulties of reconstructing the early period. Later authors describe beginnings from their own communal perspectives. We therefore cannot attribute the developed doctrines of later centuries to every participant in the earliest dispute without examining the evidence.

Succession involved more than choosing an administrator. What entitles someone to lead? How are government and the interpretation of revelation related? Who recognises a successor, and on what grounds? Different answers can reshape religious life even when communities draw on a common original inheritance.

A limited contemporary analogy may clarify the question. After a community’s founder departs, members agree that the founder’s work must continue but disagree about how. Some give decisive weight to a recognised procedure, others to the special designation of a successor. The dispute concerns both the next leader and the basis of that leader’s powers. This analogy neither explains divine guidance nor equates Islam with an organisation; it illustrates the structure of a question.

We should not make it a ready-made judgment. Procedural recognition need not mean equality among all participants in a modern political sense. Special designation need not amount to family privilege. Within a religious tradition, both positions have grounds that deserve to be heard in their own language.

The historical starting point identifies the difference without making it simple. Generations of work lie between an event, its remembrance and a developed teaching. History requires us to follow these transitions rather than treat the later map as an exact photograph of the first day.

Does gradual doctrinal development make a teaching less meaningful to a believer? Historical description alone cannot decide. A religious participant may understand development as clarification of a true foundation; a researcher describes the sequence of available evidence and changing formulations. Confusing these questions produces a dispute in which one party dates a text and the other answers about its religious truth. The date matters, but by itself neither confirms nor refutes revelation. Precision begins by identifying the claim being investigated and avoiding an automatic transfer of the answer from one question to another.

II. Authority: Who May Interpret the Inheritance?

In Shiʿi traditions, the imamate involves the special significance of the Prophet’s family and Ali. Its content and lines of succession nevertheless differ between branches. Sunni traditions give an important place to the Qurʾan, the Sunna and recognised scholars’ work. The absence of one institution for all Muslims does not imply an absence of authorities or methods of scrutiny.

Three grounds of recognition help clarify matters. Someone may have expertise through study, hold an institutional office, or possess a particular religious status according to a community’s faith. These grounds can combine, but they are not synonyms. Conflating them makes every discussion a dispute about the single word “power.”

In our hypothetical situation, a teacher knows a source’s language but does not lead the community. A leader organises its work without claiming deep expertise in every text. A third person is revered as a spiritual guide. Asking who is “highest” cannot explain their relationships. We must establish each person’s task and recognised powers.

Religious beliefs about an imam go beyond ordinary respect for a teacher. When a community believes in special guidance, an outside researcher should represent that belief as belief, rather than proclaim it a scientifically established fact or disguise it as everyday competence. The researcher can study how authority appears in texts and practices without making the community’s religious judgment on its behalf.

Conversely, recognising a scholar does not guarantee every retelling or make every judgment equally applicable in all circumstances. Language, context, faithful transmission and knowledge of the situation remain necessary. Authority operates through recognised relationships and work; a listener’s emotional certainty does not exhaust it.

The reader’s question becomes more specific: which form of authority is involved? Answering helps explain disagreement without declaring that some people “follow reason” while others “follow a person.” In religious life, reasoning, transmission, trust and belonging can interact more subtly than that pair allows.

Authority also relates to time. Citing an earlier author requires understanding how a statement was transmitted and applied. Recognising a living guide requires establishing which questions are addressed to that person and what weight their explanation carries. The same phrase, “we follow,” may conceal different relationships with a text, person and community. Comparison therefore begins by describing that relationship rather than judging a degree of obedience. We can then identify the disagreement—who interprets, for example, or how an interpretation’s reliability is preserved—and discuss its grounds without first attributing a lack of independence to the other side.

III. Sunni Diversity: Law and Theology

Sunni tradition includes four widely known legal madhhabs: Hanafi, Maliki, Shafiʿi and Hanbali. The Amman Message’s first point lists them among other schools. A madhhab is a school of jurisprudence; its name does not automatically disclose every view of each person affiliated with it.

Daftary’s survey also discusses Ashʿari and Maturidi theology. Legal and theological classifications answer different questions. We cannot place them in one list as though a person must choose either a legal school, a theological approach or a spiritual practice. Historical connections matter without making the categories identical.

Imagine a library with one shelf devoted to practical prescriptions, another to God’s attributes and the grounds of faith, and a third to personal formation. An author may consult all three. The shelves organise questions without enclosing the author’s life in a sealed compartment.

Disagreement over a particular prescription does not mean that participants practise entirely different religions. Shared affiliation, however, does not establish that the disagreement is trivial. Its importance depends on its subject, arguments and role in practice. What appears a minor detail to an outsider may matter to the fulfilment of a religious obligation.

The word “traditional” needs particular care. It may refer to a chain of transmission, an established practice, or an author’s judgment that their position is more correct. Without clarification, it can exclude another position without explaining it. A historical account should identify who uses the description and what it means.

Sunni diversity is therefore better approached through multiple questions and disciplines than through a list of human types. A school’s name cannot predict temperament, education or attitudes towards a neighbour. It supplies an important part of the map, after which we must still read a particular text and listen to a particular person.

Visible behaviour does not always establish school affiliation accurately either. In our hypothetical scene, two people perform a similar practice but explain it differently; a third shares one explanation but adapts a particular form to circumstances. Understanding requires their words and context, rather than a photograph alone. The example asserts no religious rule. It shows an observational limit: visible form relates to its doctrinal grounds, but we cannot reconstruct that relationship from an isolated fragment at will. The more weight we attach to a difference, the more carefully we should verify that it has actually been established.

IV. Shiʿi Diversity: Lines of the Imamate and Ways of Knowing

The Institute of Ismaili Studies’ Shiʿi Studies Unit research programme identifies three principal branches: Twelver, Ismaili and Zaydi. This begins a distinction rather than exhaustively listing every historical group. “Shiʿis believe” often needs qualification: which branch, author and period?

Twelvers recognise a line of twelve imams beginning with Ali and believe in the last imam’s occultation and future reappearance. Zaydi understandings of an imam’s qualifications and succession differ; Daftary describes the roles of descent, religious knowledge and active assertion of a claim to leadership. We cannot reduce these positions to a single father-to-son succession scheme for all Shiʿis.

Ismaili history also contains internal differences. Daftary’s “Ismaʿili History” discusses the Nizari–Mustaʿli division following a succession dispute in 1094. “An Ismaili imam” consequently needs historical context; Ismaʿil cannot be declared the last imam of every subsequent Ismaili community.

Legal methods also differed within Twelver history. Aron Zysow’s “Ejtehād” examines disputes about ijtihad’s legitimacy and limits, the grounding of conclusions and transmitted reports’ status. This is not a confrontation between “thinking” and “unthinking” people, but disagreement about how authoritative inheritance should be preserved and understood.

Our analytical conclusion is modest: a shared name does not abolish internal questions. Learning one school or one guide does not entitle us to present it as a detailed account of all Shiʿis. Even a common statement of faith can find expression in different languages, institutions and explanatory methods.

Diversity does not make differences accidental or all positions identical. Participants may see the dispute as concerning fidelity to their religious foundation. Respectful inquiry need not diminish that seriousness. It should convey it without attributing every position ever associated with a tradition’s name to each individual bearing it.

V. Karbala: Event, Memory and Religious Meaning

In 680, Husayn, Ali’s son and the Prophet’s grandson, died in a confrontation with Umayyad forces at Karbala. Meir Litvak’s “Karbala” examines the event, pilgrimage and the city’s developing significance in Shiʿi history. Historical description of his death and religious understanding of martyrdom relate to each other but remain different types of claim.

Husayn’s remembrance is especially important in Shiʿi religious life. Yet its forms cannot be reduced to one conspicuous scene. Reading, narration, gatherings, pilgrimage and ritual each have meanings and histories. A spectacular fragment selected by an outsider rarely explains the whole practice.

A hypothetical family example illustrates the distinction between event and memory. A family preserves the story of someone who acted courageously in difficult times. A date establishes when it happened; an annual gathering shows how the story enters descendants’ lives; courage expresses an evaluation. These levels connect, but the date does not exhaust the gathering’s meaning.

Religious memory is not reducible to family remembrance. The analogy only helps explain why “what actually happened?” and “what does it mean for the community?” require different accounts. An outside researcher can investigate a ritual’s circumstances and changing forms, while attributing its religious significance to believers’ perspective.

Nor should a significant memory become every participant’s fixed psychological portrait. Remembering suffering does not prove that someone lives entirely through resentment. Honouring courage does not predict their position in every contemporary disagreement. Individuals participate in communal inheritance in many ways.

Responsible inquiry thus begins with what a practice means to those who perform it, then examines historical changes and disagreements. The order matters: assigning a ritual our own explanation in advance makes people’s subsequent answers illustrations of a finished theory rather than possible corrections to our understanding.

Memory has another limit: the seriousness of another person’s reverence does not oblige an observer to simulate faith. The observer can listen closely, respect agreed arrangements and honestly acknowledge understanding only part of the meaning. Participants, in turn, need not replace a religious explanation with a more convenient secular one to earn respect. Encounter becomes possible when people distinguish recognising someone’s concern from agreeing with every belief. The discussion then becomes neither a loyalty test nor a demand to prove rationality before a self-appointed judge.

VI. Shared Words Do Not Erase Different Foundations

Sunni and Shiʿi traditions turn to the Qurʾan, the Prophet Muhammad and religious life before God. Point 2 of the Amman Message emphasises the listed schools’ shared foundations and practices. This is normative work towards mutual recognition, rather than a statement that every historical theological disagreement concerned only minor details.

Words such as “imam,” “sunna” and “community” occur across traditions without necessarily playing identical roles. A table of shared words does not establish shared meanings; different meanings do not prove a complete absence of a common subject either. We must investigate usage rather than choose either extreme beforehand.

Consider “teacher.” In one setting it means an instructor, in another a spiritual guide, in a third a revered author from the past. Whether a pupil should follow the teacher depends on the relationship intended. The shared word alone does not establish it.

The stakes rise in translating religious concepts. A Russian term may evoke familiar associations with another tradition or secular institution. “Clergy” and “church” can provide an initial explanation while obscuring important features of Islamic authority. An analogy helps while its limits are explicit; then we must return to the subject’s own concepts.

A shared inheritance does not imply an identical body of transmitted reports or an identical assessment of every historical person. Such differences need careful reading of particular sources. Another community’s religious life cannot be judged by whether it reproduces our familiar form of transmission.

Good comparison retains both similarity and difference. Communities may draw on a shared foundation while understanding interpreters’ powers differently; practices may share a name but differ in conditions. This language is less dramatic than proclamations of complete unity or estrangement, but lets readers examine the subject itself.

This also limits a universal summary. Keeping only general terms for simplicity can suggest that serious differences barely exist. Listing differences alone erases the shared religious world in which they matter. We need several guiding questions, showing where answers converge and diverge. An introduction need not be exhaustive, but its selection should be intelligible. Here those questions are succession, interpretation, jurisprudence and memory. They enable further reading without promising that a brief survey replaces knowledge of every tradition.

VII. Reading Sources Without Choosing a Hidden “Norm”

A description may be internal, polemical or scholarly. An internal text explains what to believe or do within a position. A polemical text defends one side and challenges another. A scholarly study reconstructs context, scrutinises evidence and compares interpretations. One author can combine purposes, so we should identify genre through the text’s work rather than its cover alone.

For example, Ali al-Sistani’s guidance on following a jurist is a primary source for a particular Twelver position. It illuminates distinctions between foundations of faith and practical prescriptions. It does not thereby describe every Shiʿi branch, every period or the relationships between them from an outside research perspective.

Daftary separately examines idealised communal images of the past and later classifications of other groups. Our methodological conclusion follows: when an author calls one side true and another mistaken, researchers must attribute those descriptions to that author. Otherwise, a judgment quietly becomes history’s impersonal voice.

The danger increases when the reader’s most familiar group becomes an unnamed background. Its text then appears simply “Islamic,” while every other text receives a qualifier. Inequality precedes comparison: one position is already the starting point, another must justify its existence.

Accurate attribution can correct this. Who wrote the text? Which community and school does it represent? When was it written? Who is being challenged? Are there sources from the described side itself? These questions do not require declaring every position equally true; they require recognising that an author’s affiliation is a perspective.

Primary texts and scholarly surveys also serve different purposes. A primary text presents self-description and argument; research clarifies context and limitations. Reading only a survey risks losing the tradition’s internal language. Reading only its account of itself risks missing formation and disagreement. Comparing these kinds of work makes description more substantial.

We need not demand a source without any perspective. More useful is the ability to scrutinise its claims within stated limits. A scholar may belong to a tradition and handle evidence carefully; an outsider may claim impartiality while repeating another group’s polemical classification. Affiliation alone does not settle a study’s value. Examine how it distinguishes testimony from inference, acknowledges uncertainty and handles objections. Such work makes perspective visible and lets readers understand why they trust a conclusion.

More precisely, al-Sistani’s guide represents a Twelver Usuli position. “Usuli” here identifies a particular approach to principles of legal inquiry; historical disputes with Akhbaris prevent treating it as every Shiʿi community’s sole way of knowing.

VIII. How Broad Names Conceal Internal Differences

Internal diversity becomes clearer through two particular documents than through broad labels alone. This applies beyond Islamic history. Comparison can scrutinise our classification without making one religion another’s model.

The Augsburg Confession, Articles IX–X, affirms infant baptism and the true presence of Christ’s body and blood in the Supper. Baptist Faith and Message, VII, describes believers’ baptism by immersion and a symbolic Supper. Both are Christian documents with shared vocabulary and significant disagreements. “Protestant” therefore cannot predict every answer, just as “Sunni” cannot automatically identify someone’s legal school or theological approach. Protestant history does not replicate Islamic divisions: this compares a classification error rather than identical origins of a split.

Authority needs equally precise reading. Dei Verbum, §§9–10, relates Catholic teaching authority to Scripture and Tradition. Al-Sistani’s guide organises ijtihad and following a jurist in a particular way. The limited similarity is that texts and competent interpretation remain connected. Neither Catholic institutions nor Twelver Usuli practice provide a universal scheme for every community in their religion. The latter cannot be extended to Ismailis, Zaydis or the whole historical Shiʿi spectrum.

Islamic material thus needs at least three coordinates: a branch’s historical formation, its stated source of authority and the particular question being considered. Legal disagreement differs from theological disagreement; belonging to a line of the imamate does not answer questions about legal knowledge.

This changes the museum visitor’s next step. Rather than ask which label correctly describes everyone, he can ask when a classification arose, which position an object represents and what its community says it means. The broad name remains a useful signpost without excusing further reading. Respect does not require cancelling differences. It requires understanding which differences are under discussion and whom a source can represent.

IX. Affiliation Does Not Complete a Person’s Story

“Sunni” and “Shiʿi” matter: they name memories, teachings, ways of recognising authority and religious life. Without them, differences disappear from view. When a name explains a whole person, however, it ceases to assist understanding and substitutes for an encounter.

History shows gradual formation and internal disagreement. Believers give this inheritance meaning beyond chronology. Our contemporary analysis distinguishes levels without equating them or translating religious life entirely into external usefulness.

Respect requires two efforts: learning actual differences without dissolving them into a benevolent slogan, and avoiding transferring everything known about a tradition to an individual without conversation. Even extensive knowledge can become inaccurate at the moment of encounter.

Readers should distinguish two kinds of inference. One precise guide establishes that a position exists within a specified tradition. It does not show that everyone bearing its broad name shares it. A different position requires qualifying the general claim, but does not establish that the tradition has no stable rules. Al-Sistani’s guide, for example, remains meaningful evidence of Twelver Usuli work after we stop attributing it to all Shiʿis. Narrowing its scope preserves its value. It also helps us choose the next question: do we need this jurist’s position, a school’s history, or our interlocutor’s personal practice? Each requires appropriate evidence, even when a catalogue places them under one heading.

Our opening visitor returns to the two museum labels. They now open questions about succession, law, memory, knowledge and particular communities. He lacks many answers but is less inclined to think two words have told him everything. Sometimes understanding begins with this shift: a name no longer closes off a person but helps identify a precise question about their world.

What this means in practice

Before discussing someone’s religious affiliation, identify a particular subject. Rather than demand an explanation of “all Shiʿis” or “all Sunnis,” ask what a practice or teaching means within their community. The person need not become an appointed representative of millions they do not know.

Distinguish three levels in their answer: personal life, a school’s position and history. Someone may know their participation in a practice better than its origins. A historian may confidently explain those origins without speaking for every current participant. These are different competencies, not rivals.

When reading a claim about another tradition, find a source from that side and at least one substantive scholarly discussion. The aim is not mechanically balancing two quotations, but checking whether a group is credited with claims it does not make, a polemical remark becomes a definition, or conditions and period disappear.

Replace a broad sentence with a more definite one. Instead of “Shiʿis recognise this authority,” name the branch, author and meaning of authority. Instead of “Sunnis disagree,” identify the question and source. Keep insufficient information visible. Precision precedes final judgment.

Also check whether you infer character from affiliation. Judging an action requires information about the action. A person’s position emerges from their words and conduct. A religious name can help frame a question, but should not supply an answer we have yet to receive.

This is our contemporary exercise in reading and conversation, rather than a religious ruling on groups’ status. It does not require believers to abandon convictions. Serious disagreement can coexist with an accurate account of another side. Attention to a person does not depend on a promise that everyone will adopt one position afterwards.

Key quotation

“Compete with one another in good deeds.”

Qurʾan 5:48, excerpt; Dr. Mustafa Khattab’s English translation, The Clear Quran. Editorial English rendering of the approved Russian version, which the article’s author translated from English. Its context concerning revelations and communities does not establish that all doctrines are identical.

Connections across traditions

These are our analytical comparisons. Historical influence is not asserted without supporting evidence.

Subject	Positions and sources	What can be compared	Boundary
Broad family and particular position	Islamic diversity: Daftary — Augsburg Confession IX–X — BFM VII	A family’s common name does not predict all its members’ beliefs.	Protestant differences do not reproduce Sunni and Shiʿi branches’ origins; the comparison concerns classification.
Text and competent interpretation	Al-Sistani: opening of Islamic Laws — Dei Verbum 9–10	A source’s authority accompanies an order of interpretation.	Twelver Usuli practice and Catholic teaching authority differ institutionally and theologically.
Legal method within Shiʿi history	Usulis and Akhbaris: Zysow — Al-Sistani: normative example	Legal knowledge has internal disputes about method.	A contemporary Usuli example does not describe every Shiʿi current or replace a historical map.
Recognition and agreement	Amman Message, points 1–2 — Augsburg Confession VII	Boundaries of community can be discussed separately from complete uniformity.	Muslim recognition and Lutheran church unity have different criteria; normative documents establish no worldwide agreement.
Difference and action	Qurʾan 5:48 — AN 3.65	Assessing action matters alongside affiliation and formulas.	Revelation and Buddhist scrutiny of harm and benefit do not assert a common religious system.
Knowing others and representation	Qurʾan 49:13 — IIS: Shiʿi branches	Understanding requires distinctions more specific than a broad name.	The verse concerns peoples and tribes; the research programme defines a field. Its historical list is not derived from the verse.

Sources

Primary texts, normative documents and scholarly commentary are identified in the descriptions. The heading does not turn a reference study into a primary source.

The Pluralism Project, Harvard University. Sunni and Shi’i Interpretations. Only the introductory explanation of succession and Ali’s relationship to the Prophet is used. Some later simplified descriptions of branches are not used. Introduction.
Farhad Daftary. Diversity in Islam: Communities of Interpretation. IIS electronic text; © 2004 Encyclopaedia Iranica, © 2006 The Institute of Ismaili Studies. Selected portions on formation, sources, Zaydis, Twelvers and Sunni diversity were read. Scholarly survey.
The Three Points of the Amman Message, V.1. Points 1–2 supply recognised schools and shared foundations. This contemporary normative document is not treated as universal historical consensus. Text.
The Institute of Ismaili Studies, Shiʿi Studies Unit. Our Research. Used for its three principal branches and study of internal diversity. Research programme.
Farhad Daftary. Ismaʿilism iii. Ismaʿili History. Encyclopaedia Iranica. The opening and passage on the 1094 division are used. Scholarly article.
Aron Zysow. Ejtehād. Encyclopaedia Iranica. Opening sections on Twelver jurists’ disputes are used. Scholarly article.
Meir Litvak. Karbala. Encyclopaedia Iranica. Opening historical sections on the event of 680, pilgrimage and memory are used. Scholarly article.
Ali al-Sistani. Islamic Laws, Chapter One: Following a Jurist (Taqlīd). A particular primary Twelver example, rather than a description of all Shiʿis. Official text.
Qurʾan 49:13; Dr. Mustafa Khattab’s English translation, The Clear Quran. Primary religious text on peoples, tribes and knowing one another. Text and passage used.
Qurʾan 5:48; Dr. Mustafa Khattab’s English translation, The Clear Quran. Primary religious text on law, way and good deeds in the context of revelations. Text and passage used.
Augsburg Confession, Articles VII, IX–X. Primary Lutheran confessional document on church unity, baptism and the Lord’s Supper. Text and passages used.
Southern Baptist Convention. Baptist Faith and Message, VII. Primary Baptist confessional document on believers’ baptism by immersion and the symbolic Supper. Text and passage used.
Second Vatican Council. Dei Verbum, §§9–10. Primary Catholic normative document on Scripture, Tradition and teaching authority. Text and passages used.
AN 3.65, Kālāma / Kesamutti Sutta; translated by Thanissaro Bhikkhu. Primary Buddhist text on evaluating qualities and actions through harm, benefit and the judgment of the wise. Text and passage used.

About the authors

Andrey Zarinsh is the author and founder of United Wisdom. He explores inner transformation, the unity of traditions, intercultural dialogue and contemporary spiritual discipline. Instagram: @andrey.zarinsh.

Maria Evilkut is the co-author of United Wisdom. Alongside her research, she seeks to test these ideas in practice and observe how principles of unity and mutual understanding work in real life between people and cultures. Instagram: @ilkutki.