Jihadism, its importance in the history of Islam or why it is now striking our societies with the virulence it is doing are common elements in the media; questions that, although repeated, are alien to us, which many, especially many journalists —especially them— are unaware of and should be aware of.

Familiarity with the history of Jihad, from Mohammed to the current Islamic State, passing through Visigothic Hispania, the Crusades, the Ottoman Empire and the Cold War, is necessary to understand the Europe of today and surely the Spain of tomorrow.

These 20 truths serve as an introduction:

1 What is called ‘Islamic clerics’ does not have the same meaning as in Christianity. Muhammad died without founding a church. Imams, mullahs, etc. are faithful like any others, but more versed in the scriptures and often especially pious… in their own way.

2 Since there is no Church, there is no hierarchy for all to recognise: for all practical purposes, the word of a crude Somali ulema raised in the Muslim Brotherhood is as good as that of a learned scholar from Al-Azhar. In short, no one has the power to ‘excommunicate’ a jihadist.

3 Muhammad dies without separating religion and politics. There is no ‘to God what is God and to Caesar what is Caesar’s’. It is all the same. Those who say that Islam is a political religion are right. That is why it is so difficult for it to integrate into non-Muslim political orders.

4 Since Islam is a political religion, Muslims tend to group together wherever they are in order to reconstitute their umma, their community. It is illusory to think of a ‘civil integration’ of Muslim communities into secular or Christian societies. They are their own world.

5 This communitarian tendency is fundamental to understanding such things as the importance of the veil, a sign of common identity, or the adherence to the community of those Muslims who are apparently not religious at all. In a political religion, the political is as important as the religious.

6 The essential source of Islam is the Koran, Allah’s revelation to Muhammad, but there is also the Sunna, a compendium of the Prophet’s sayings and deeds, the deeds of the Sahaba, Muhammad’s companions, and the tradition gathered from life in Medina, the first city founded by Muhammad.

7 All the doctrinal sources take us back to the 7th century. They were frozen there, because Allah manifested himself to Muhammad once and for all time. And since there is no Church that can make this legacy evolve, the whole doctrinal corpus remains petrified in the atmosphere of that time.

8 The major division in Islam also dates back to the 7th century: the Sunnis, who after Muhammad’s death recognised his father-in-law Abu-Bakr as caliph (successor), and the Shiites, who opted for Ali, the Prophet’s nephew and son-in-law —hence they are also called Ali or Fatimids, after Muhammad’s daughter.

9 According to the majority Shia tradition, Muhammad and Ali were followed by up to twelve Imams. The last one disappeared in 874 and his return has been awaited ever since. In time, the Shia world became confined to the areas of Persian, not Arab, culture (today Iran).

10 This uniqueness of the Shia world means that something like a clergy has developed there: the ayatollahs, hoyatoleshlam, etc., scholars whose function is to interpret the signs that the imam sends from some point beyond time, and who exercise political authority.

11 The opposition between Sunni and Shia is not transient, but essential: they are two irreconcilable ways of understanding Islam, which is why they have been at war for 1,400 years. It is another matter whether they will eventually be able to see eye to eye in the face of a common enemy.

12 Salafism is not a political ideology. Salaf means ancestor, predecessor, and the term is applied to the first three generations of Muslims who lived the original Islam and also to the first authors who codified Islam from the beginning of the ninth century.

13 The term Salafism was born in the 19th century and designates those who preach a return to the original sources of Islam. But these currents were present from very early on, even if they did not call themselves ‘Salafists’. It is neither a deviation nor an ‘extremism’. It is fundamentalism.

14 Shari’a (Islamic law) is not an ‘interpretation’ of Islam either: it is, in fact, the only possible interpretation for applying Islamic rules to social life. That is why it is still in force at the popular level even in those countries that have adopted modern legislation.

15 The common idea that ‘the march of progress’ will eventually secularise Islam as it has secularised Christianity is not true. For one thing, because the idea of ‘progress’ is a concept intimately linked to the Christian view of history – in no other culture is there such a concept.

16 The reality is that all attempts to secularise Muslim societies, which were very intense in the 20th century, have failed: Iran, Iraq, Syria, Egypt, Libya, even Turkey, etc. The re-Islamisation of the Muslim world is the major event of the 20th century in that civilisation.

17 Jihadism is not a deviation or an anomaly. Jihad means ‘striving’ (for the faith) and the concept includes both the personal conquest of virtue and the violent imposition of faith. It has been present in Islam since its origin and is not a ‘misinterpretation’.

18 Jihadism implies considering the infidel as an inferior being, devoid of human dignity, because he is not part of the umma (community). To annihilate him poses no problem of conscience. This also extends to the apostate, the Muslim who is considered a traitor.

19 The Muslim believes in the existence of Jesus, but not as God, but as a man. To believe in the divinity of Christ is blasphemy and deserves to be punished. It is not true that Islam is compatible with Christianity.

20 Traditionally, Islam reserves for Christians and Jews, religions born from the stem of Abraham, a singular role: dhimmitude, that is, respecting their lives in exchange for the payment of a tax and not making an external profession of faith. It is not true that Islam is ‘tolerant’.

There is much more to say, but for the time being, this list will suffice to illustrate some fundamental truths about Islam that everyone should know. It is a religion with its own logic, not exactly that of societies born of Christian civilisation.