He is known as attorney general of the Province of Quebec, judge, mathematician, historian, member of the Royal Society, and cursitor baron of the exchequer.

On 4 March 1766, he was appointed attorney general of the new British Province of Quebec, the former French Canada conquered in 1760 and definitively ceded by France through the Treaty of Paris in 1763.

He espoused the cause of Pierre du Calvet who intended to bring governor Frederick Haldimand before the courts for violating the British constitution.

This took a strictly nominalistic view of algebraic operations, saying that negatives were invalid "in any other light than as the mark of subtraction of a lesser quantity from a greater."

In 1756 in Montréal, together with a coven of jurists and scholars, he founded a lodge that would later go down in history as Masarez (Mispronunciation of the founder's name, due to the oral handing down of codes), which would operate for several decades, on Canadian as well as British soil.