Hatata

Yacob wrote Hatata as an investigation of the light of reason. Yacob is most noted for this philosophy surrounding the principle of harmony. He asserted that an action's morality is decided by whether it advances or degrades overall harmony in the world. While he did believe in a deity, whom he referred to as God, he rejected any set of religious beliefs. Rather than deriving beliefs from any organized religion, Yacob sought the truth in observing the natural world. In Hatata, Yacob applied the idea of a first cause to produce a proof for the existence of God, thus proposing a cosmological argument. "If I say that my father and my mother created me, then I must search for the creator of my parents and of the parents of my parents until they arrive at the first who were not created as we [are] but who came into this world in some other way without being generated." However, the knowability of God does not depend on human intellect, but "Our soul has the power of having the concept of God and of seeing him mentally. God did not give this power purposelessly; as he gave the power, so did he give the reality."

Upon Yacob's death in 1692 his pupil Walda Heywat updated the work to include his death.

Though it is generally taken by most scholars of Ethiopic literature and of Africana Philosophy to an authentic work written by a certain Abyssinian from Aksum in the 17th Century, there have been doubts over his authorship since the early 20th Century. This comes from the fact that the Franciscan Jesuit monk Giusto Da Urbino had not sent the original manuscripts to his patron and collector Antoine D'Abbadie, but 'copies' he had made by his own hand. The other reason that doubts emerged arose from a rumour by a monk Teklehaymanot, who claimed that he had heard other people say that he might written the treatise himself. This and other plot-holes in the story of the acquisition by D'Abbadie and curious exchanges between D'Urbino and his patron, make authentic authorship all the more doubtful. For instance, the fact that there was an anticipated place in D'Abbadie's then growing collection of Ethiopia literature for 'scientific' and other rare subjects to be placed in, and the all-too-coincidental fact that D'Urbino was able to deliver and satisfy this need of his financial sponsor. Scholars who fall into this camp of the doubtful have included Enno Littmann, and presently Anaïs Wion,[1] a prominent French scholar of Ethiopic Literature. On the other side, those who affirm Zara Yacob's authentic authorship of the original texts include the Canadian Scholar Claude Sumner who translated the treatises into English, and Ethiopian Scholar and Philosopher Teodros Kiros. Both of the latter strongly argue for their authenticity and have written extensively on the texts.

• Kidane, Dawit Worku. The Ethics of Zar’a ya’əqob. Pontifical Gregorian University. Rome, 2012.
• Encyclopaedia Aethiopica: D-Ha. Otto Harrassowitz Verlag. 2003, p. 1046.

• Enno Littmann. Philosophi Abessini. Corpus Scriptorum Christianorum Orientalium, Vol. 18, Scriptores Aethiopici, Presses Républicaines, 1904. Contains the Ge'ez text of the Hatata.
• Claude Sumner, Ethiopian Philosophy, vol. II: The Treatise of Zara Yaecob and Walda Hewat: Text and Authorship, Commercial Printing Press, 1976.
• Claude Sumner, Ethiopian Philosophy, vol. III: The Treatise of Zara Yaecob and Walda Hewat: An Analysis, Commercial Printing Press, 1978.
• Claude Sumner. Classical Ethiopian Philosophy, Commercial Printing Press, 1985. Contains an English translation of, and brief introduction to, the Hatata and three other texts.

• Petri Liukkonen. "Yacob Zara". Books and Writers
• Ethiopian Philosophy – A blog with commentary on the Hatata