Theory:Doctor Who television discontinuity and plot holes/The Masque of Mandragora


 * The astrologer has a telescope, and the Doctor doesn't like it very much; "A pity, in another fifty years we could've used Galileo's". Galileo was however one of the first to use a telescope and use it for astronomical observations. The telescope is therefore an anachronism.
 * Galileo was indeed one of the first known to use a telescope, and the Doctor's line about him confirms that this was not a mere oversight by the writer. It's quite conceivable that others had made telescopes before Galileo without it being recorded in history.
 * The primitive telescope prop is actually first seen in Giuliano's room (and is taken to Hieronymous' room by the Doctor). Early in the serial, Giuliano is reading reports of an unspecified scholar / inventor who has made such a device, leading to a discussion about astronomy between him and Marco. It would seem that Giuliano himself has had a not-particularly-successful attempt at making a telescope of his own, requiring the Doctor to adjust and compensate for its deficiencies.


 * The Doctor concluding that Sarah Jane is under an alien influence simply because she is curious about how she can speak Italian seems a little unjustified.
 * The Doctor senses a disruption in the low-level telepathic field that unites him and Sarah through the TARDIS, allowing him to share his 'Time Lord gift' of understanding every language with her, and her asking that question is merely a final confirmation of his concern.
 * It seems more likely that a disruption in the telepathic field would impair her ability to speak Italian rather than cause curiosity about how she had acquired that ability.


 * The fact that no companion has ever thought to ask this question before might be taken to imply that part of the "Time Lord gift" entails being brainwashed into not even noticing it, so as to spare the weary Time Lord the additional bother of having to answer this question as often as he is forced to explain dimensional transcendentalism to ignorant alien groupies.


 * In declaring his "revolutionary" belief in a spherical Earth, Giuliano is actually voicing a well-accepted belief for his time and place. Dante, writing in the previous century (in the Inferno and Purgatorio), had described the Earth as a sphere, and that had been the prevailing theory since Classical times. In fact, there is evidence that as far back as 3000 BC, the Greek philosopher Aristachus had made it a well known fact that the earth was spherical, and that it was not the centre of the solar system.
 * Probably true, however given the uneducated and superstitious nature of the local area he lived in, there were likely a large number of his people who did not hold with that belief.


 * Giuliano tells Sarah Jane that he secretly believes that the world is round, as do a growing number of scientists. This is historically inaccurate: By the time of the late 16th century, the spherical nature of the Earth was common knowledge and not at all considered heretical; even the Church held the Earth to be round. The remark was probably meant as a clever reference to Columbus' discovery of the New World the same year, which is actually a popular myth that he proved the Earth to be round. The real reason people had laughed at Columbus wasn't because they thought the Earth was flat; it was because they knew from scientific measurements that the Earth was so big that a journey to Asia would be so long that the crew would starve to death.
 * To be fair, given the woeful ignorance encouraged in the duchy by Federico and Hieronymous, it is small wonder Giuliano's research is tailing somewhat behind the cutting-edge even of Renaissance science.