Newton not only gave the distinguished Royal Society a telescope that had no chromatic aberration, he also gave them a theory according to which refracting telescopes had to have this undesirable flaw. It was, accordinng to Newton, due to the fact that in a lens telescope, different colors inherent in white light were refracted to their focal points at different distances from the lens, causing the colored fringes. Likewise, as white light is separated into colors in a prism, this must also happen in lenses.

However, by choosing a pinpoint light source, Newton failed to see, that he had dramatically limited the overall phenomenon he was supposed to explain. He thus came to understand the continuous spectrum as the primary phenomenon in a prism, which according to Goethe, it was not.