He acquired a great reputation as a lawyer, less by practice in the courts than in a consultative capacity,[1] and served the ancien régime as member of a committee to revise the civil and criminal laws of the kingdom.
[citation needed] He was counsel for Louis René Edouard, cardinal de Rohan in the "affair of the diamond necklace".
He went on to support revolutionary measures such as the union of the orders, the suspensive veto, the Civil Constitution of the Clergy, the last of which he was one of the principal authors.
His excessive obesity, which made him the butt of the Royalist jokes, prevented his practising at the bar for some years before 1789.
In 1792, he published some constitutional observations in extenuation of the king's actions, which, in the circumstances of the time, would have taken some courage.