The ideals of the Enlightenment are the basis of our democracies and universities in the 21st century: belief in reason, science, skepticism, secularism, and equality. In fact, no other era compares with the Age of Enlightenment. Classical Antiquity is inspiring, but a world away from our modern societies. The Middle Ages was more reasonable than its reputation, but still medieval. The Renaissance was glorious, but largely because of its result: the Enlightenment. The Romantic era was a reaction to the Age of Reason – but the ideals of today’s modern states are seldom expressed in terms of romanticism and emotion. Immanuel Kant’s argument in the essay ‘Perpetual Peace’ (1795) that ‘the human race’ should work for ‘a cosmopolitan constitution’ can be seen as a precursor for the United Nations.

As the story usually goes, the Enlightenment began with René Descartes’s Discourse on the Method (1637), continuing on through John Locke, Isaac Newton, David Hume, Voltaire and Kant for around one and a half centuries, and ending with the French Revolution of 1789, or perhaps with the Reign of Terror in 1793. By the time that Thomas Paine published The Age of Reason in 1794, that era had reached its twilight. Napoleon was on the rise.

But what if this story is wrong? What if the Enlightenment can be found in places and thinkers that we often overlook? Such questions have haunted me since I stumbled upon the work of the 17th-century Ethiopian philosopher Zera Yacob (1599-1692), also spelled Zära Yaqob.

Yacob was born on 28 August 1599 into a rather poor family on a farm outside Axum, the legendary former capital in northern Ethiopia. At school he impressed his teachers, and was sent to a new school to learn rhetoric (siwasiw in Geéz, the local language), poetry and critical thinking (qiné) for four years. Then he went to another school to study the Bible for 10 years, learning the teachings of the Catholics and the Copts, as well as the country’s mainstream Orthodox tradition. (Ethiopia has been Christian since the early 4th century, rivalling Armenia as the world’s oldest Christian nation.)

In the 1620s, a Portuguese Jesuit convinced King Susenyos to convert to Catholicism, which soon became Ethiopia’s official religion. Persecution of free thinkers followed suit, intensifying from 1630. Yacob, who was teaching in the Axum region, had declared that no religion was more right than any other, and his enemies brought charges against him to the king.

Yacob fled at night, taking with him only some gold and the Psalms of David. He headed south to the region of Shewa, where he came upon the Tekezé River. There he found an uninhabited area with a ‘beautiful cave’ at the foot of a valley. Yacob built a fence of stones, and lived in the wilderness to ‘front only the essential facts of life’, as Henry David Thoreau was to describe a similar solitary life a couple of centuries later in Walden (1854).

For two years, until the death of the king in September 1632, Yacob remained in the cave as a hermit, visiting only the nearby market to get food. In the cave, he developed his new, rationalist philosophy. He believed in the supremacy of reason, and that all humans – male and female – are created equal. He argued against slavery, critiqued all established religions and doctrines, and combined these views with a personal belief in a theistic Creator, reasoning that the world’s order makes that the most rational option.

In short: many of the highest ideals of the later European Enlightenment had been conceived and summarised by one man, working in an Ethiopian cave from 1630 to 1632. Yacob’s reason-based philosophy is presented in his main work, Hatäta (meaning ‘the enquiry’). The book was written down in 1667 on the insistence of his student, Walda Heywat, who himself wrote a more practically oriented Hatäta. Today, 350 years later, it’s hard to find a copy of Yacob’s book. The only translation into English was done in 1976, by the Canadian professor and priest Claude Sumner. He published it as part of a five-volume work on Ethiopian philosophy, with the far-from-commercial Commercial Printing Press in Addis Ababa. The book has been translated into German, and last year into Norwegian, but an English version is still basically unavailable.

Ethiopia was no stranger to philosophy before Yacob. Around 1510, the Book of the Wise Philosophers was translated and adapted in Ethiopia by the Egyptian Abba Mikael. It is a collection of sayings from the early Greek Pre-Socratics, Plato, and Aristotle via the neo-Platonic dialogues, and is also influenced by Arabic philosophy and the Ethiopian discussions. In his Hatäta, Yacob criticises his contemporaries for not thinking independently, but rather accepting the claims of astrologers and soothsayers just because their predecessors did so. As a contrast, he recommends an enquiry based on scientific rationality and reason – as every human is born with intelligence and is of equal worth.

Far away, grappling with similar questions, was Yacob’s French contemporary Descartes (1596-1650). A major philosophical difference is that the Catholic Descartes explicitly denounced ‘infidels’ and atheists, whom he called ‘more arrogant than learned’ in his Meditations on First Philosophy (1641). This perspective is echoed in Locke’s A Letter Concerning Toleration (1689), which concludes that atheists ‘are not at all to be tolerated’. Descartes’s Meditations was dedicated to ‘the dean and doctors of the sacred Faculty of Theology in Paris’, and his premise was ‘to accept by means of faith the fact that the human soul does not perish with the body, and that God exists’.

In contrast, Yacob shows a much more agnostic, secular and enquiring method – which also reflects an openness towards atheistic thought. Chapter four of the Hatäta starts with a radical question: ‘Is everything that is written in the Holy Scriptures true?’ He goes on to point out that all the different religions claim theirs is the true faith:

Indeed each one says: ‘My faith is right, and those who believe in another faith believe in falsehood, and are the enemies of God.’ … As my own faith appears true to me, so does another one find his own faith true; but truth is one.

In this way, Yacob opens up an enlightened discourse on the subjectivity of religion, while still believing in some kind of universal Creator. His discussion of whether or not there is a God is more open-minded than Descartes’s, and possibly more accessible to modern-day readers, as when he incorporates existentialist perspectives:

Who is it that provided me with an ear to hear, who created me as a rational being and how have I come into this world? Where do I come from? Had I lived before the creator of the world, I would have known the beginning of my life and of the consciousness of myself. Who created me?

In chapter five, Yacob applies rational investigation to the different religious laws. He criticises Christianity, Islam, Judaism and Indian religions equally. For example, Yacob points out that the Creator in His wisdom has made blood flow monthly from the womb of women, in order for them to bear children. Thus, he concludes that the law of Moses, which states that menstruating women are impure, is against nature and the Creator, since it ‘impedes marriage and the entire life of a woman, and it spoils the law of mutual help, prevents the bringing up of children and destroys love’.

In this way, Yacob includes the perspectives of solidarity, women and affection in his philosophical argument. And he lived up to these ideals. After Yacob left the cave, he proposed to a poor maiden named Hirut, who served a rich family. Yacob argued with her master, who did not think a servant woman was equal to an educated man, but Yacob prevailed. When Hirut gladly accepted his proposal, Yacob pointed out that she should no longer be a servant, but rather his peer, because ‘husband and wife are equal in marriage’.

In contrast to Yacob’s views, Kant wrote a century later in Observations on the Feeling of the Beautiful and Sublime (1764): ‘A woman is embarrassed little that she does not possess certain high insights.’ And in Kant’s lectures on ethics (1760-94) we read that: ‘The desire of a man for a woman is not directed to her as a human being, on the contrary, the woman’s humanity is of no concern to him; and the only object of his desire is her sex.’

Yacob wrote ‘all men are equal’ decades before Locke, the ‘Father of Liberalism’, put pen to paper

Yacob looked upon the woman in a completely different way, namely as a philosopher’s intellectual peer. Hirut, he wrote: ‘was not beautiful, but she was good-natured, intelligent and patient’. Yacob cherished his wife’s intelligence, and he stressed their mutual and individualistic love for one another: ‘Since she loved me so, I took the decision in my heart to please her as much as I could, and I do not think there is another marriage which is so full of love and blessed as ours.’

Yacob is also more enlightened than his Enlightenment peers when it comes to slavery. In chapter five, he argues against the idea that one can ‘go and buy a man as if he were an animal’. That is because all humans are created equal and with the capacity to reason. Hence, he also puts forward a universal argument against discrimination based on reason:

All men are equal in the presence of God; and all are intelligent, since they are his creatures; he did not assign one people for life, another for death, one for mercy, another for judgment. Our reason teaches us that this sort of discrimination cannot exist.

The words ‘all men are equal’ were written decades before Locke (1632-1704), the ‘Father of Liberalism’, put pen to paper (indeed, he was born the same year that Yacob returned from his cave). But Locke’s social-contract theory did not apply to all in practice: he was secretary during the drafting of The Fundamental Constitutions of Carolina (1669), which gave white men ‘absolute power’ over their African slaves. And he invested heavily in the English Trans-Atlantic slave trade through the Royal African Company. In the Second Treatise (1689), Locke argues that God gave the world ‘to the use of the industrious and rational’ – which the philosopher Julie K Ward at Loyola University in Chicago argues can be read as a colonial attack on the right to land of American Indians. Compared with his philosophical peers, then, Yacob’s philosophy often reads like the epitome of all the ideals we commonly think of as enlightened.

Some months after reading the work of Yacob, I finally got hold of another rare book this summer: a translation of the collected writings of the philosopher Anton Amo (c1703-55), who was born and died in Guinea, today’s Ghana. For two decades, Amo studied and taught at Germany’s foremost universities, writing in Latin. His book, Antonius Gvilielmus Amo Afer of Axim in Ghana, bears a subtitle that describes the author: ‘Student. Doctor of philosophy. Master and lecturer at the universities of Halle, Wittenberg, Jena. 1727-1747.’ According to the World Library Catalogue, just a handful of copies, including those in the original Latin, are available in libraries around the world.

Amo was born a century after Yacob. He seems to have been kidnapped from the Akan people and the coastal city of Axim as a young boy, possibly for slavery, before being brought via Amsterdam to the court of Duke Anton Ulrich of Braunschweig-Wolfenbüttel. Amo was baptised in 1707, and he received a very high-standard education, learning Hebrew, Greek, Latin, French, High and Low German, in addition to probably knowing some of his mother tongue, Nzema. The great polymath G W Leibniz (1646-1716) frequently visited Amo’s home in Wolfenbüttel when he was growing up.

Amo matriculated at the University of Halle in 1727, and became well-respected in German academic circles of the time, holding lecturing positions both at the universities of Halle and Jena. In Carl Günther Ludovici’s 1738 book on the Enlightenment thinker Christian Wolff (1679-1754) – a follower of Leibniz and a founder of several academic disciplines in Germany – Amo is described as one of the most prominent Wolffians. While in the dedicatory preface to Amo’s On the Impassivity of the Human Mind (1734), the rector of the University of Wittenberg, Johannes Gottfried Kraus, hailed Amo’s compendious knowledge and ‘the praises he received thanks to his genius’. He also set Amo’s contribution to the German Enlightenment in a historical context:

In the past, the veneration given to Africa was enormous, whether for its natural genius, its appreciation for learning, or its religious organisation. This continent nurtured the growth of a number of men of great value, whose genius and assiduousness have made an inestimable contribution to the knowledge of human affairs.

Kraus stresses ‘the development of Christian doctrine, how many were its promoters who came from Africa!’ And he cites intellectuals such as Augustine, Tertullian, and the Amazigh (Berber) Apuleius as examples. The rector also underscores the European Renaissance’s African heritage, ‘as the Moors coming from Africa crossed through Spain, they brought knowledge of the ancient thinkers, while also bringing much assistance to the development of letters which were coming out of the darkness little by little’.

Amo wrote of other theologies than the Christian, including the Turks and the ‘heathens’

Such words from the heart of Germany in the spring of 1733 might make it easier for us to remember that Amo was not the only African to achieve success in 18th-century Europe. At the same time, Abraham Petrovich Gannibal (1696-1781), also kidnapped from sub-Saharan Africa, became the general of Peter the Great of Russia. Gannibal’s great-grandson became Russia’s national poet, Alexander Pushkin. And the French author Alexandre Dumas (1802-70) was the grandson of an enslaved African woman, Louise-Céssette Dumas, and son of a black aristocratic general born on Haiti.

Neither was Amo alone in bringing diversity or cosmopolitanism to the University of Halle in the 1720s and ’30s. Several talented Jewish students studied there and received doctorates. The Arab teacher Salomon Negri of Damascus and the Indian Soltan Gün Achmet from Ahmedabad were others who arrived in Halle to study and teach. Amo himself developed a close relationship with Moses Abraham Wolff, a Jewish medical student, who was one of the students he supervised. And in his thesis, Amo wrote explicitly that there were other theologies than the Christian, including among them the Turks and the ‘heathens’.

Amo discussed such cosmopolitan issues when he defended his first thesis, the legal dissertation On the Right of Moors in Europe in 1729. Amo’s dissertation is not available today. It might be that the defence was given only orally, or that the text has simply been lost. But in the Halle weekly paper of November 1729 there is a short report from his public disputation, which was granted to him so that the ‘argument of the disputation should be appropriate to his situation’. According to the newspaper report, Amo argued against slavery with reference to Roman law, tradition and rationality:

Therein it was not only shown from books and history that the kings of the Moors were enfeoffed [given freedom in exchange for pledged service] by the Roman Emperor, and that every one of them had to obtain a royal patent from him, which Justinian also issued, but it was also investigated how far the freedom or servitude of Moors bought by Christians in Europe extends, according to the usual laws.

Did Amo hold Europe’s first legal disputation against slavery? We can at least see an enlightened argument for universal suffrage, like the one Yacob had advanced 100 years earlier. However, such non-discriminatory perspectives seem to have been lost on the central Enlightenment thinkers later in the 18th century.

In his Essays and Treatises on Several Subjects (1753-4), Hume wrote: ‘I am apt to suspect the negroes, and in general all the other species of men (for there are four or five different kinds) to be naturally inferior to the whites.’ He added: ‘There never was a civilised nation of any other complexion than white, nor any individual eminent either in action or speculation.’ Kant (1724-1804) built on Hume (1711-76), and stressed that the fundamental difference between blacks and whites ‘appears to be as great in regard to mental capacities as in colour’, before concluding in Physical Geography: ‘Humanity is at its greatest perfection in the race of the whites.’

In France, the most famous Enlightenment thinker, Voltaire (1694-1778), not only described Jews in anti-Semitic terms, as when he wrote that ‘they are all of them born with raging fanaticism in their hearts’; in his Essay on Universal History (1756), he also wrote that if Africans’ ‘intelligence is not of another species than ours, then it is greatly inferior’ (fort inférieure). Like Locke, he invested his money in the slave trade.

Amo’s philosophy is often more theoretical than Yacob’s, but they share an enlightened perspective of reason, treating all humans alike. His work is deeply engaged with the issues of his day, as in Amo’s best-known book, On the Impassivity of the Human Mind (1734), which is built upon a logically deductive method using strict arguments, seemingly in line with his former juridical dissertation. Here he grapples with Cartesian dualism, the idea that there is an absolute difference in substance between mind and body.

At times, Amo seems to oppose Descartes, as the contemporary philosopher Kwasi Wiredu points out in A Companion to African Philosophy (2004), when he writes: ‘Human beings sense material things not with respect to their mind but with respect to their living and organic body.’ Wiredu argues that Amo opposed the Cartesian dualism between mind and body, rather favouring the Akan metaphysics and Nzema language of his early childhood: that you feel pain with your flesh (honam), not with your mind (adwene).

But at the same time, Amo says that he will both defend and speak against Descartes’s view (from his Letters, Part I) that the soul (mind) is able to act and suffer together with the body. Hence, Amo writes: ‘In reply to these words we caution and dissent: we concede that the mind acts together with the body by the mediation of a mutual union. But we deny that it suffers together with the body.’

The examples of Yacob and Amo make it necessary to rethink the Age of Reason

Amo argues that Descartes’s statements in these matters are contrary to the French philosopher’s ‘own view’. He concludes his thesis by stating that we should avoid confusing the things that belong to the body and the mind. For whatever operates in the mind must be attributed to the mind alone. Perhaps it is as the philosopher Justin E H Smith at the University of Paris points out in Nature, Human Nature and Human Difference (2015): ‘Far from rejecting Cartesian dualism, on the contrary Amo offers a radicalised version of it.’

But could it also be that Wiredu and Smith are both right? For example, if the traditional Akan philosophy and Nzema language had a more precise Cartesian body-mind distinction than Descartes, a way of thinking that Amo then brought into European philosophy? It might be too early to tell, as a critical edition of Amo’s works is still pending publication, possibly at Oxford University Press.

In Amo’s most thorough work, The Art of Philosophising Soberly and Accurately (1738), he seems to anticipate the later Enlightenment thinker Kant. The book deals with the intentions of our mind, and with human actions as natural, rational or in accordance with a norm. In the first chapter, writing in Latin, Amo argues that ‘everything knowable is either a thing in itself, or a sensation, or an operation of the mind’.

He elaborates in the next paragraph, stating that ‘for the sake of which cognition occurs, is the thing in itself’. And in the following demonstration: ‘Real learning is cognition of things in themselves. It thus has the basis of its certainty in the known thing.’ Amo’s original wording is ‘Omne cognoscibile aut res ipsa’, using the Latin notion res ipsa for the ‘thing-in-itself’.

Today, Kant is known for his notion of the ‘thing-in-itself’ (das Ding an sich) in Critique of Pure Reason (1787) – and his argument that we cannot know the thing beyond our mental representation of it. Yet it is acknowledged that this was not the first use of the term in Enlightenment philosophy. As the Merriam-Webster Dictionary writes on the term thing-in-itself: ‘First known use: 1739.’ Still, that is two years after Amo’s main work was turned in at Wittenberg, in 1737.

The examples of these two Enlightenment philosophers, Yacob and Amo, might make it necessary to rethink the Age of Reason in the disciplines of philosophy and history of ideas. Within the discipline of history, new studies have shown that the most successful revolution to spring from the Enlightenment ideas of liberty, equality, and fraternity was in Haiti rather than in France. The Haitian Revolution (1791-1804) and the ideas of Toussaint L’Ouverture (1743–1803) paved the way for the state’s independence, new constitution, and the abolition of slavery in 1804. The historian Laurent Dubois concludes in Avengers of the New World (2004) that the events in Haiti were ‘the most concrete expression of the idea that the rights proclaimed in France’s 1789 Declaration of the Rights of Man and Citizen were indeed universal’. In a similar vein, one might wonder: will Yacob and Amo also one day be elevated to the position they deserve among the philosophers of the Age of Enlightenment?