Question about Java polymorphism and casting

Question

I have a class C. Class E extends it.

E e = new E();
C c = new C();

Why is

e = (E) c;

Upon further review

Answer 1

To add to Frederik's answer, casting an object to something doesn't change it's type. Also, object's can only be cast to a type it already is (the compiler just doesn't know at that point) That's why impossible casts will never be accepted:

Integer i = (Integer) new String();

will not compile, because the compiler knows it can't be possible.