The ground for taking ignorance to be restrictive of freedom is that it causes people to make choices which they would not have made if they had seen what the realization of their choices involved.
If the assertion that there is a god is nonsensical, then the atheist's assertion that there is no god is equally nonsensical, since it is only a significant proposition that can be significantly contradicted.
It is time, therefore, to abandon the superstition that natural science cannot be regarded as logically respectable until philosophers have solved the problem of induction. The problem of induction is, roughly speaking, the problem of finding a way to prove that certain empirical generalizations which are derived from past experience will hold good also in the future.
We say that a sentence is factually significant to any given person, if, and only if, he knows how to verify the proposition which it purports to express.