Born in 1641 in Alençon, France, he became a pastor first at Saint-Agobile Champagne, and then at Charenton, near Paris. The revocation of the Edict of Nantes in 1685 compelled him to take refuge in London, England where, under the sanction of King James II, he opened a church for the French exiles.
His reputation for learning was such as to obtain for him, soon after his arrival, the degree of doctor of divinity from both universities, and in 1690 he received from Bishop Burnet the more substantial honour of the treasurership and a canonry in Salisbury Cathedral.
The works of Allix, which are numerous, are chiefly of a controversial and apologetic character, and must be used with caution. In opposition to French Catholic bishop Jacques-Benigne Bossuet he published Some Remarks upon the Ecclesiastical History of the Ancient Churches of Piedmont (1690), and Remarks upon the Ecclesiastical History of the Ancient Churches of the Albigenses (1692), with the idea of showing that the Albigensians were not Manichaeans, but historically identical with the Waldenses. This opinion is not held by modern scholars, who are certain that the Albigensians were not orthodox Christians, whether or not they were Manichaeans.