Speaker: Carsten Butz Title: An introduction to Quine's "New Foundations". Abstract: In 1937 the logicien and philosopher Quine introduced a set-theory (nowadays called "New Foundations" NF) as a foundation for mathematics, alternative to systems based on type theories (like Russell's theory of types) or theories like Zermelo Fraenkel set-theory ZF. The system can be easily motivated if we look at the history of foundations of mathematics at the beginning of this century, but it has to be admitted that is difficult to motivate NF ontologically. NF has a curious feature: the whole universe V = { x | x=x } is a set, in particular V is a member of itself. NF disproves the axiom of choice (and proves infinity), which is maybe one of the main reasons that people lost interest in this system. But... New Foundations is not known to be consistent (relative to some other accepted system like ZF). Various related systems are known to be consistent, notably New Foundations with atoms (Jensen 1969). This talk will be an introduction to this interesting system.