Turkey's schools have begun the new academic year with a controversial curriculum that leaves out the theory of evolution and brings in the concept of jihad.
For Turkey's Islamist-rooted government, the idea is for a new "education of values".
Critics have denounced new textbooks as "sexist" and "anti-scientific", and complain of a major blow to secular education.
"By embedding a jihadist education of values, they try to plague the brains of our little children, with the same understanding that transforms the Middle East into a bloodbath," said Bulent Tezcan of the secular, opposition CHP party.
But the government has accused the opposition of creating black propaganda and trying to polarise Turkey ahead of elections in 2019.
"When we say values, they understand something else. We are proud of our conservative-democrat stand, but we don't want everyone to be like us," says Education Minister Ismet Yilmaz.
Reclaiming jihad from jihadists
Textbooks explaining the idea of jihad are being rolled out in Turkey's religious vocational schools, known widely as Imam-Hatip high schools. They will then be offered to children in secondary schools as optional courses in a year's time.
One book titled Life of Muhammad the Prophet has been singled out for criticism, both for alleged sexism and its explanation of jihad.
Jihad is defined as "religious war" by the dictionary of the Institute of Turkish Language. But education ministry officials say the concept of jihad has been exploited by jihadist groups such as so-called Islamic State (IS).
The education minister says the concept should be introduced as part of Islam in the context of "loving a nation".
"Jihad is an element in our religion. Our duty is to teach every concept deservedly and correct things that are wrongly perceived," he says.
The same controversial textbook defines women's "obedience" to men as a form of "worship". But government officials say that is understandable as the book is about Islam and quotes Koranic verses.
"Allah says it, not me. Should I correct him, or what?" said Alpaslan Durmus, who chairs the Board of Education.
But two big protests went ahead at the weekend, with hashtags such as #NoToSexistCurriculum, #SayNoToNonScientificCurriculum and #DefendSecularEducation trending on social media in Turkey.
One union leader called for protesters to "say No to an outdated curriculum that bans science in the 21st Century".
Opponents have accused President Recep Tayyip Erdogan's ruling Justice and Development Party (AKP) of replacing the secular foundations of the Turkish republic with Islamic and conservative values.
The president's own remarks on raising a "pious generation" have also caused alarm.
The education ministry also argues that critics are "utterly ignorant" for claiming that evolution has been completely excluded from the curriculum.
Subjects such as mutation, modification and adaptation are explained in biology textbooks, without citing evolution itself. This theory is "above students' level" and should be taught in universities, says the minister.
This will only confuse students, says Aysel Madra from Turkey's Education Reform Initiative, who finds it odd to posit that children can understand jihad but not evolution.
Teachers' unions are also divided over the jihad debate.
Turkey's Egitim Sen union sees an "ideological and deliberate" step by the government, while a more conservative rival union accuses critics of using anti-Islamic arguments.
"According to the Turkish Language Institute, jihad's primary meaning is 'religious war'," says Egitim Sen leader Feray Aydogan. "What is the point of explaining second and third meanings?"