the hypothesis forms the working basis for all of black hole physics and astrophysics. If cosmic censorship were to not hold, then some of the very massive stars will end as black holes, while others could end as naked singularities. As we will argue in Section 3, these two kinds of objects have very different observational properties.

There are various very important reasons for investigating whether or not cosmic censorship holds in classical general relativity. As we have mentioned above, the hypothesis is vital for black hole astrophysics. Unfortunately this fact is rarely appreciated by the astrophysics community. The hypothesis is also necessary for the proof of the black hole area theorem. It is not clear what the status of this theorem will be if the hypothesis were to not hold. If naked singularities do occur in classical relativity, they represent a breakdown of predictability, because one could not predict the evolution of spacetime beyond a naked singularity. Such singularities would then provide pointers towards a modification of classical general relativity, so that a suitable form of predictability is restored in the modified theory. Further, naked singularities might be observable in nature, if they are allowed by general relativity. Undoubtedly 