Editing Almagest (section)

== Modern assessment ==
Under the scrutiny of modern scholarship, and the cross-checking of observations contained in the Almagest against figures produced through backwards extrapolation, various patterns of errors have emerged within the work.{{sfn|Wade|1977}}{{sfn|Lewis|1979}} A prominent example is Ptolemy's use of measurements said to have been taken at noon, but which systematically produce readings that are off by half an hour, as if the observations were taken at 12:30pm.{{sfn|Wade|1977}} However, an explanation for this error was found in 1969.{{sfn|Goldstein|1978}}{{sfn|Britton|1969}}{{sfn|Britton|1992}}

The overall quality of Claudius Ptolemy's scholarship and place as "one of the most outstanding scientists of antiquity" has been challenged by several modern writers, most prominently by [[Robert R. Newton]] in the 1977 book ''The Crime of Claudius Ptolemy'', which asserted that the scholar fabricated his observations to fit his theories. Newton accused Ptolemy of systematically inventing data or doctoring the data of earlier astronomers, and labelled him "the most successful fraud in the history of science".{{sfn|Wade|1977}} One striking error noted by Newton was an autumn equinox said to have been observed by Ptolemy and "measured with the greatest care" at 2pm on 25 September 132, when the equinox should have been observed at 9:54am the day prior.{{sfn|Wade|1977}}
Herbert Lewis, who had reworked some of Ptolemy's calculations, agreed with Newton that "Ptolemy was an outrageous fraud", and that "all those results capable of statistical analysis point beyond question towards fraud and against accidental error".{{sfn|Lewis|1979}}

Although some have described the charges laid by Newton as "erudite and imposing", others have disagreed with the findings.{{sfn|Wade|1977}} [[Bernard R. Goldstein]] wrote, "Unfortunately, Newton’s arguments in support of these charges are marred by all manner of distortions, misunderstandings, and excesses of rhetoric due to an intensely polemical style."{{sfn|Goldstein|1978}} [[Owen Gingerich]], while agreeing that the Almagest contains "some remarkably fishy numbers",{{sfn|Wade|1977}} including in the matter of the 30-hour displaced equinox, which he noted aligned perfectly with predictions made by [[Hipparchus]] 278 years earlier,{{sfn|Gingerich|1980}} rejected the qualification of fraud.{{sfn|Wade|1977}}{{sfn|Gingerich|1981}}
John Phillips Britton, Visiting Fellow at Yale University, wrote of R.R. Newton, "I think that his main conclusion with respect to Ptolemy’s stature and achievements as an astronomer is simply wrong, and that the Almagest should be seen as a great, if not indeed the first, scientific treatise." He continued, "Newton’s work does focus critical attention on the many difficulties and inconsistencies apparent in the fine structure of the Almagest. In particular, his conclusion that the Almagest is not a historical account of how Ptolemy actually derived his models and parameters is essentially the same as mine, although our reasons for this conclusion and our inferences from it differ radically."{{sfn|Britton|1992}}