He was then sent to the Mile End academy, where John Conder was the divinity tutor, but was transferred at his own request to a similar institution at Homerton.

He continued to seek for a pastorate over a dissenting congregation in England, and about 1762 he was selected as the minister of a chapel at Southampton, where he soon publicly renounced Calvinism and adopted the doctrines of Unitarianism.

It was a condition of the marriage that Cogan should enter the profession of medicine, and he accordingly matriculated at Leyden University on 16 October 1765, and took his degree of M.D.

By 1780 he was once more in the Netherlands, having resigned his connection to Dr. John Sims, for many years the leading accoucheur in London, and retired to follow his studies in moral philosophy.

The last years of his life were mainly passed in his lodgings in London or at his brother's house at Higham Hill.

Each of them brought 15 friends to a meeting at the Chapter Coffee-house in St. Paul's Churchyard in the summer of 1774, when the Royal Humane Society was formed.

One of the five gold medals minted for the society is inscribed to the memory of Cogan, and in its annual report for 1814 is a portrait of him, with a eulogy of his talents as an author and the co-founder.

It was entitled Specimen Medicum inaugurale de animi pathematum vi et modo agendi in inducendis et curandis morbis.

Two volumes of Theological Disquisitions on Religion as affecting the Passions and on the Characteristic Excellencies of Christianity followed in 1812 and 1813 respectively, and the whole five treatises were published in a set in 1813.

A long analysis of Cogan's writings is in Jared Sparks's Collection of Essays and Tracts in Theology (1824), which also contains (pp.