Given a circle in the boundary of a manifold, we would often like to find a disk embedded in the manifold whose boundary is the given circle. If the manifold is simply connected then we can find a map from a disc to the manifold with boundary the given circle, and if the manifold is of dimension at least 5 then by putting this disc in "general position" it becomes an embedding. The number 5 appears for the following reason: submanifolds of dimension "m" and "n" in general position do not intersect provided the dimension of the manifold containing them has dimension greater than formula_1. In particular, a disc (of dimension 2) in general position will have no self intersections inside a manifold of dimension greater than 2+2.