The power of Ptolemy

How can we objectively assess the contribution to astronomy of a person whose major writing is commonly dubbed ‘The Greatest,’ whose theories held sway over astronomical thought for 1,500 years, but which are now judged as putting astronomers on the wrong path for all those years?

Claudius Ptolemy, usually just known by his surname, was born in about 100 CE and lived and died near Alexandria in Egypt. He may have