All students are welcome at the College de France provided there is room. Space is the only restriction on access.
Founded in the Renaissance, the state-owned Paris college is undergoing a second rebirth with major construction works initiated by the late President Mitterrand.
The first stage of the facelift was inaugurated by President Chirac last month. Stone under the main courtyard was hollowed out and the old foundations removed to create two large lecture theatres, a vast reception area and conference rooms.
Ancient arched and vaulted passages and chambers recall the past, while electronically-driven shutters and state-of-the-art telecoms for distance learning place the college in the future.
The work, which so far has cost 150 million francs (Pounds 15.8 million), was somehow done without having to interrupt courses.
It is claimed that the college is unique in France, and the world. It has no enrolled students and awards no diplomas. Anyone, with or without qualifications, may attend any lecture free of charge, so long as there is a seat. Audiences often include students from the Paris universities supplementing their studies, and retired people.
The only stipulation on lecturers is that they must not repeat a course and that the topics cover most recent research findings.
The ideals on which the college was founded are quality research and teaching, the promotion of scientific and academic exchange.
The state-owned but auto-nomous college is structured around 52 chairs. When one becomes vacant candidates are selected by a professors' assembly, which also determines college policy. Tenured professors have voting rights and honorary ones play a consultative role. Non-French tenured professors are permitted, and a European and international chair reserved annually for foreigners.
College chairman Gilbert Dagron, professor of Byzantine history and civilisation, was elected by his peers and named by decree of the French president.
To advance research exchanges, professors may spend up to a third of their time teaching elsewhere, perhaps in provincial universities or abroad. Several regularly operate in laboratories or centres outside Paris, including Strasbourg, Grenoble and Toulouse.
In reverse, nearly 1,000 researchers and academics from such institutions as Inserm, the medical research institute, and CNRS, the national science research centre, regularly work at the college.
Visitors from other countries are welcome; five British academics have lectured at the college during last year.
The college's origins go back to 1530 when Francois I nominated six "royal lectors", three for Hebrew, two for Greek and one for mathematics; even then courses were open to all and free of charge. Originally known as the Coll ge Royal, later the Coll ge Imperial, it grew over the years, occupying the Chalgrin building, its present main site (there are two others) next to the Sorbonne in the 1770s. It became the Coll ge de France in 1870.
By 1990 it had long been obvious that major renovation was urgently needed, and it was adopted as one of President Mitterrand's grand projects.
Now the college is preparing for two more phases of work, the next to be devoted mainly to updating the laboratories and libraries.
To celebrate its facelift the college is organising four conferences. The series began this week with "Neurosciences and society" and will finish in mid-December with "Literary identity of Europe: Unity and multiplicity".