The son of a physician, and himself a graduate from the Military College in Constantinople as an ophthalmologist, Cevdet, initially a pious Muslim, was influenced by Western materialistic philosophies and was against institutionalized religion, but thought that "although the Muslim God was of no use in the modern era, Islamic society must preserve Islamic principles". He published the periodical İçtihat from 1904–1932, in which articles he used to promote his modernist thoughts. He was arrested and expelled from his country several times due to his political activities and lived in Europe, in cities including Vienna, Geneva and Paris. His poetry was linked with the Symbolist movement in France, and he received accolades from leading French authors like Gustave Kahn. The overall goal of early Young Turks such as Cevdet was to bring to end the absolutist regime of Sultan Abdul Hamid II. Cevdet and four other medical students at the Military Medical Academy in Istanbul founded the society of Ottoman Progress in 1889, which would become the "Committee of Union and Progress". Initially with no political agenda, it became politicized by several leaders and factions and mounted the Young Turk Revolution against Abdul Hamid II in 1908. However, Abdullah Cevdet and Ibrahim Temo cut their ties with the CUP soon after 1902, as the CUP began to advocate a Turkist nationalist policy. Instead he promoted his secular ideas in his magazine İçtihat, where he published articles in support of several policies, which later were part of Atatürk's Reforms like the shutting down of the madrases or the furthering of women's rights. In 1908 he joined the Ottoman Democratic Party which was founded against the CUP. In 1912 he and Hüseyin Cahit advocated without success for the Latin script to be introduced in the Ottoman Empire. Cevdet was tried several times in the Ottoman Empire because some of his writings were considered as blasphemy against Islam and Muhammad. For this reason, he was labelled as the "eternal enemy of Islam" and called "Aduvullah". His most famous court case was due to his defense of the Bahá'í Faith, which he considered an intermediary step between Islam and the final abandonment of religious belief, in his article in İçtihat on 1 March 1922. For a brief period between 1921 and 1922 he was active for Kurdish independence.
We are pious infidels; our faith is that Being a disciple of God is tantamount to love. What we drink at our drinking party is The thirst for the infinite.
"Ranging from the New Testament to the Qur’ān, from Plato to Abū al-‘Alā’ al-Ma’arrī, he created an eclectic philosophy, reconciling science, religion, and philosophy with one another", and in order to specifically build an "Islamic materialism", he would use medieval mystical authors like Al-Maʿarri, Omar Khayyam and Rumi, and try to find correspondence in their works with modern authors such as Voltaire, Cesare Lombroso, Vittorio Alfieri and Baron D'Holbach. His "final step was to present modern scientific theories ranging from Darwinism to genetics as repetitions of Islamic holy texts or derivations from the writings of Muslim thinkers", trying to fit the Qur'an or ahadith with the ideas of peoples like Théodule Armand Ribot or Jean-Baptiste Massillon. He found that "the Qur’ān both alluded to and summarized the theory of evolution." Disillusioned by the ulema's lukewarm response to his role as "materialist mujtahid", he turned to heterodoxy, the Bektashi and then Bahaism. Being unfruitful in that regard as well, he'd spent his last efforts as purely intellectual.
Death
Left alone in his final years, Abdullah Cevdet died at the age of 63 on 29 November 1932. His body was brought for religious funeral service to Hagia Sophia, which was still used as a mosque at that time. However, nobody claimed his coffin, and it was expressed by some religious conservatives that he "did not deserve" Islamic funeral prayer. Following an appeal of Peyami Safa, a notable writer, the funeral prayer was performed. His body was then taken by city servants to the Merkezefendi Cemetery for burial.