In one of the most disputed passages of Greek literature Plato in the Republic, 7. 528e–530c prescribes astronomy as the fourth study in the education of the Guardians. But what sort of astronomy? According to one school of thought it is a purely speculative study of bodies in motion having no relation to the celestial objects that we see. While this interpretation has rejoiced the hearts of Plato's detractors, who regard him as an obstacle to the progress of science, it has dismayed his admirers. Another school of thought holds that what Plato meant was that astronomers must get to know the real motions of the heavenly bodies as opposed to their apparent motions as seen by us on earth. The opposed interpretations may be set out in the following representative citations from Sir Thomas Heath and John Burnet.