It is a fact that Galileo used several approaches to make his arguments to the Grand Duchess Christina, which he wrote in his deathbed in 1615. One of the approaches that Galileo uses is to refer to his experience. This, Galileo does not use as the compass in itself, but instead he refers to it as the event that triggered multiple researches, investigations, establishments and the growth of arts, as opposed to the diminution or destruction of the same.
It is at the above juncture that a critical observer will note the presence of the use of ethos by Galileo. By the experience that Galileo refers to above, it is obvious that one immediately considers the scientific truth that Galileo was propounding: that the earth is rotates around the sun, and that the earth was not the center of the universe. However, the inference that is induced in the mind of the reader of the “Letter to the Grand Duchess” is the sundry and all ill treatments and peril that Galileo had gone through. It is obvious that the Inquisition had totally been ruthless in dealing with Galileo. Sentencing him to house arrest for the alleged heresy was the culmination of the Inquisition’s chastisement. One would therefore be compelled to rethink and analyze Galileo’s assertions, since it is clear he was paying for the same assertions with his life. The aspect and use of ethos comes out greatly especially when one considers that Galileo had been a man of social standing and an authority in the field that the debate fell in (Carroll, 7).
At the same time, in Galileo’s arguments to the Grand Duchess Christina, it is possible to easily see the strategy of an appeal to authority. This is seen in Galileo’s First Principle that he uses in his argument. At this instance, Galileo reiterates the maxim that was advanced by Thomas Aquinas and St. Augustine that truths cannot be contradictory to each other, or against each other. Galileo reiterates and agrees with the same postulation that had been advanced by Thomas Aquinas and St. Augustine that God is the author of all truths (both spiritual and scientific); and that as such, there is no way truths can be contradictive to each other. This gives Galileo greater bargaining power and thus helps a critic understand that the problem lies with the clergy (Woodall, 2).