[2] His ambition to become a professional soldier was thwarted by frail health, which, combined with the piety of his parents, led to pursuing a religious career; to that effect, the vicar-general of Fréjus aided Emmanuel-Joseph, out of obligation to his father, Honoré.

[3] He quickly gained a reputation at the school for his aptitude and interest in the sciences, combined with his obsession over the "new philosophic principles" and dislike for conventional theology.

While there, he became influenced by the teachings of John Locke, David Hume, Edward Gibbon, Voltaire, Jean-Jaques Rousseau, Condillac, Quesnay, Mirabeau, Turgot, the Encyclopédistes, and other Enlightenment political thinkers, all in preference to theology.

He spent time researching philosophy and developing music until about a year later in October 1774 when, as the result of demands by powerful friends, he was promised a canonry in Brittany.

At the end of 1775, Sieyès acquired his first real position as secretary to the bishop of Tréguier where he spent two years as deputy of the diocese.

Due to the fact that the bishop of Tréguier had high regards for Sieyès, he was able to act as a representative of his diocese in the Upper Chamber of the Clergy.

This proposal, and Jacques Necker's invitation to French writers to state their views as to the organization of society by Estates, enabled Sieyès to publish his celebrated January 1789 pamphlet, Qu'est-ce que le tiers-état?

[9] He played his main role in the opening years of the Revolution, participating in the final drafting of the Declaration of the Rights of Man and of the Citizen,[10] expanding on the theories of national sovereignty, popular sovereignty, and representation implied in his pamphlet, with a distinction between active and passive citizens that justified suffrage limited to male owners of property.

Sieyès's pamphlet incited a radical reaction from its audience because it involved the "political issues of the day and twisted them in a more revolutionary direction".

In this case, the radical position taken by the Third Estate created a sense of awareness that the problems of France were not simply a matter of addressing "royal tyranny", but that unequal privileges under the law had divided the nation.

Sieyès's pamphlet played a key role in shaping the currents of revolutionary thought that propelled France towards the French Revolution.

He attacked the foundations of the French Ancien Régime by arguing the nobility to be a fraudulent institution, preying on an overburdened and despondent bourgeoisie.

The pamphlet placed sovereignty not in the hands of aristocrats but instead defined the nation of France by its productive orders composed of those who would generate services and produce goods for the benefit of the entire society.

By addressing the issues of representation directly, Sieyès inspired resentment and agitation that united the third estate against the feudalistic traditions of the Ancien Régime.

Sieyès advocated for equality of voting power, a unicameral legislative body, and the absence of a royal veto over the actions of the legislature.

[13] Although not noted as a public speaker as he spoke rarely and briefly, Sieyès held major political influence, and he recommended the decision of the Estates to reunite its chamber as the National Assembly; he opposed the abolition of tithes and the confiscation of Church lands.

[14] Elected to the special committee on the constitution, he opposed the right of "absolute veto" for the King of France, which Honoré de Mirabeau unsuccessfully supported.

He had considerable influence on the framing of the departmental system; after the spring of 1790, he was eclipsed by other politicians, and was elected only once to the post of fortnightly president of the Constituent Assembly.

[9] Ultimately, Sieyès failed to establish the kind of bourgeois revolution he had hoped for, one of representative order "devoted to the peaceful pursuit of material comfort".

[9] Nevertheless, Sieyès considered ways to overthrow the Directory, and is said to have taken in view the replacement of the government with unlikely rulers such as Archduke Charles of Austria and Karl Wilhelm Ferdinand of Brunswick (a major enemy of the Revolution).

He attempted to undermine the constitution, and thus caused the revived Jacobin Club to be closed while making offers to General Joubert for a coup d'état.

[20] In order to once again begin the function of government, these three men took the oath of "Inviolable fidelity to the sovereignty of the people; to the French Republic, one and indivisible; to equality, liberty and the representative system".

The main responsibility of the College des Conservateurs was to choose the members of the two legislative bodies, and protect the constitution by right of absorption.

By this curious provision, the College could forcibly elect to its ranks any individual deemed dangerous to the safety of the state, who would then be disqualified from any other office.

Sieyès soon retired from the post of provisional Consul, which he had accepted after 18 Brumaire, and became one of the first members of the Sénat conservateur (acting as its president in 1799); this concession was attributed to the large estate at Crosne that he received from Napoleon.

[23] After the plot of the Rue Saint-Nicaise in late December 1800, Sieyès defended the arbitrary and illegal proceedings whereby Napoleon rid himself of the leading Jacobins.

When the Académie Française was reorganized in 1803, he was elected in the second class, replacing, in chair 31, Jean Sylvain Bailly, who had been guillotined on 12 November 1793 during the Reign of Terror.

However, after the second Restoration in 1815, Sieyès was expelled for his role in the execution of King Louis XVI, and was replaced by the Marquis of Lally-Tollendal, who was named to the Academy by a royal decree.