When inside a class method, there is no "denormalised" way to get at other methods "statically" i.e.:

class foo(){
function bar(){
// do not use $this;
}
function otherbar(){
foo::bar();//            <--- allow self::bar()
}
}

foo::otherbar();

If foo was an extension of some other class foobase, it could get at the foobase::methods with the "parent::" construct. In other words to get at my parent's method I do not need to know its name, but if I am not an instance I can not get at my own methods without giving my name. 

Since you can call a class method without an instance, this seems a natural extension of php's ::

Thank you all