This concept of deceit and manipulation is backed up by the fact that throughout the initial speech by the Duke he seems to actively aim to make Escalus feel of less value than he is worth. An example of this is “But that, to your sufficiency, as your worth is able”. The use of words such as “sufficiency” appear to be designed to make Escalus feel like he is only just good enough and nothing more than that. That way the Duke does not disenchant him completely with the world of politics but instead keeps him in his place. This theory is backed up once more by Escalus’s response to the dukes rhetorical questioning in which he says “If any in Vienna be of worth […] It is Lord Angelo”. This line, I believe, would be read in an almost sarcastic way as if he is mocking Angelo and the Duke.
Once Angelo arrives; the Dukes tone, while no less powerful and demanding, becomes more focussed on flattering Angelo than it does demoralising Escalus. The Dukes attempts at flattery such as, “Thyself and thy belongings are not thine own so proper as to waste”, promote the idea that the Duke really wants Angelo to take the position; perhaps he fears that if Angelo won’t then he will have to promote Escalus to the position instead. This section of the scene also introduces the idea and theme of Actions versus Words. This is primarily shown when Angelo says “Let there be some more test made of my metal” implying that, while he is simply employing fake modesty, he is saying he should be tested further before he is given this position. The way the Duke says “We have with leavened and preparèd choice proceeded to you”, I believe, is his way of saying we have talked enough on the matter brings the play back to Actions versus Words.
Some people are of the opinion that the Duke is simply a bad leader who is fleeing when times turn bad. “Our haste from hence is of so quick condition that it […] leaves unquestioned matters of needful value” is one such occasion where this point is made as the Duke is leaving them and it appears he has not even come up with a valid reason to tell even his closet advisors and Lords. I believe that, while one cannot escape the fact that he is displaying all the qualities of a terrible ruler, this is not the primary reason for him leaving.
On balance I believe that the Duke’s departure in this scene is due to the manipulative nature of his character and is driven by his desire to be loved by the people. The Duke does however claim that he does “not like to stage [himself] to their eyes” but I believe this to be simple lies told by him to make himself look better and more modest in front of the other Lords, more people who he wants to love him. I believe this theory encompasses other plausible theories such as the idea that he is simply a bad leader and the theory that suggests he fears the people do not need a Duke anymore as through this theory the people would think him a great leader and they would realise that they did need a Duke. Due to this I believe it is the best theory to explain the Duke’s sudden departure.
Act One Scene One Line One (1.1.1)