Thomas' father died when he was five, leaving the family badly off. The boy was educated at St Mannelier Grammar School, and then studied by himself, until he was able to pass the Bishop's Ordination Examination. In 1779 he became Rector of St John. His brother George was Constable of the parish from 1781 to 1784.
Partisans
In the early days of the struggle between the Charlots and the Magots many of the Rectors were eager partisans of the democratic party.
- "The Clergy", wrote William Charles Lempriere, the Lieut-Bailiff, to the President of the Council on 22 June 1784) "are the great patriots of the day, who conscientiously sacrifice every consideration to what they call Liberty, that is the pleasure of throwing everything into confusion by their ill-fated interference in Politicks. Your Lordship will no doubt admire their zeal when you know that on Sunday they marched in a public Market Place with blue cockades in a disgraceful and undignified manner, huzzaing for Liberty like Bacchanalians, and wearing the badge even in the Pulpit, no doubt with a view of inspiring their auditors with Christian meekness and moderation. The effect of this unclergymanlike behaviour with the populace is to be dreaded. That frantic zeal which they inspire is of the worst and most ungovernable kind, and I am convinced it will be necessary to apply a speedy and efficacious remedy to an evil, which might become at length uncurable".
Of these ultra-political parsons Sivret was the most demonstrative. He was the orator of the Magot Party. A big man of magnificent presence with "a voice like the booming of the waves", he thundered forth sonorous periods, which were by no means empty rhetoric, but full of pith and sting. His Party used its new printing-press to multiply copies of his orations, and spread them broadcast through the island.
"Like a true athlete", said La Patrie later, "he fought against the powers of darkness, and shone forth as a champion among those early Reformers, who dared to make a frontal attack on the innumerable abuses in the laws that governed us".
Schools controversy
In 1787 he was involved in a dispute with Dean Francois Le Breton. The Canons ordered the Rector, Surveillants, and Principaux to appoint a schoolmaster in every parish. The Dean interpreted this to mean that no one else was allowed to teach. George Ahier, who had opened a school in Trinity, was summoned before the Ecclesiastical Court, and ordered to close his school. Sivret denounced this as "nothing less than an attempt to keep the people in ignorance and barbarism", and described the judgement as "odious and infamous".
He took pupils in his rectory, so he was summoned before the Court as an unlicensed schoolmaster. The case attracted wide attention. His defence was that he did not claim to be parish schoolmaster, but that he had a perfect right to instruct children entrusted to him. He was eventually acquitted, and his school became a flourishing one.
He also crossed swords with William Le Marchand, Bailiff of Guernsey, who had published over the signature A B an anonymous attack on the Magots in general and Sivret in particular. Sivret replied with a witty open letter to the Bailiff appealing to him to discover and punish the author of these atrocious libels. He followed this up with an Examen de la Lettre de A B aux Anticharlots 1788.
So his life went on, an unbroken series of controversies and orations, until he died on 16 January 1790, and was buried in St John's Church.
He married Anne, daughter of Edward Le Maitre, Seigneur of La Hougue Boete, but had no children.
