The Swiss foreign minister, Joseph Deiss, is one of the main speakers on Thursday, opening this year's ISC symposium at the University of St Gallen.
The International Students' Committee (ISC) event, with 1,000 participants, is focusing on the theme: "Pushing Limits - Questioning Goals".
Deiss will speak about the "feasible and desirable" in Swiss foreign policy.
Nato secretary general Lord Robertson had been scheduled to speak at the opening session on the organisation's partnerships and cooperation. However, he cancelled his trip to Switzerland for personal reasons.
"The whole team is rather disappointed that (Robertson) cannot make it," Eric Schwaninger from the ISC organising team told swissinfo.
The ISC event, affectionately called "Three days in May" is traditionally a place of dialogue between leaders and students.
Dialogue not stones
Its roots date back to 1968 when student riots swept across Europe. Five students at St Gallen decided that dialogue should be given a chance, rather than confrontation.
"Instead of throwing stones at each other, these five students tried to get the leaders of the day from business, politics and science together with students at one table to discuss how they could improve our world and our social environment instead of fighting each other," ISC team member Gregor Simmen told swissinfo.
"Dialogue has always been in the centre at the ISC symposium," he added.
This year's event will ask questions about how far people can push limits while questioning the real reasons for doing so.
Simmen cited the enlargement of the European Union as one example and globalisation and its limits as another. From the world of science, he picked the topic of biotechnology.
"Biotechnology has improved so much in the past years that we are asking ourselves: How far do we actually want to go? Do we want to set ourselves limits to where we want to research or shall we just go on and do whatever is possible in science?"
Wings of Excellence
Apart from the 600 leaders expected, the ISC will also welcome 250 student participants who have been chosen on the basis of a competition.
"These students are selected through the biggest essay competition of its kind worldwide," Simmen told swissinfo.
"In over 600 universities we promote this essay contest - the ISC Wings of Excellence Award - and we receive over 1,000 essay entries every year."
"From those we select the best 250 contributions and those students are invited to come to St Gallen with travel, expenses and stay in the city paid," he added.
Another traditional event at the ISC symposium is the presentation of the annual Max Schmidheiny Foundation freedom prize.
The foundation, created in 1978 by the celebrated captain of Swiss industry, pays tribute to public figures or institutions who, through their influence, have made a special contribution to the promotion or preservation of a liberal, economic and social order.
This year's award winner is the United Nations High Commissioner for Refugees, Ruud Lubbers.
by Robert Brookes