The main author of the Shakespeare canon was an adept. By this I mean a man of wisdom who possesses esoteric knowledge about human evolution.
There is a practical base of knowledge to which most people aspire, such as cooking, sewing, law, medicine, or accounting. Then there is an esoteric or mystical knowledge base that relatively few seek. The main author of the Shakespeare works had sought and found it, as Peter Dawkins makes clear in his “The Wisdom of Shakespeare” series.
A knowledge of how human nature works from a higher perspective is on display in The Tempest. The Tempest divides characters into four types of people that personify the four cycles of human evolution, which Dawkins also calls the alchemical cycle, since people can “transmute” or change. The first grouping is the servants, Stephano, Trinculo and Caliban—the “gross” or “animal” class of men of the first cycle. Caliban had tried to rape Miranda, he and the others get drunk together, steal clothes, and plot murder. Caliban is “this thing of darkness” which Prospero acknowledges to be his; i.e., the dark side of nature with which humans are born. Although these three do not change during the course of the play, at the end Caliban promises to be wise and seek for grace, offering the hope that he has learned from his experience and may start to change.
The second group is the lords, of the “ordinary” state, or the second cycle. They are intelligent, reasoning human beings who are blessed with high birth, and they fall into two types. The first subset is made up of Antonio, Alonso and Sebastian. Antonio had unjustly deposed his brother Prospero; Alonso helped him carry out the plot, while Alonso’s brother Sebastian is cut from the same cloth. These are the three “bad” lords. To them, the island is a stinking marsh and desert. They are pessimistic, believing that Alonso’s son, Ferdinand, died during their shipwreck. They are spiteful, self-centered, and corrupt.
The other type of lords, Gonzalo, Adrian and Francisco, who attend the lords of the first type, are “good.” They are optimistic that Ferdinand may still be alive, and to them the island has sweet air and is lush. They possess the building blocks of faith, hope and charity. Toward the end of the play, when the “bad” Alonso resigns his kingdom and asks for forgiveness, he transmutes to their higher type.
The third group is composed of the two lovers, Miranda and Ferdinand, who are initiates. Dawkins writes:
This third cycle is that of initiation, which can only begin with a pure heart. From the pure heart can flow a pure love, which in turn enables truth to be seen [“Blessed are the pure in heart, for they will see God” (Matthew 5:8)]. This allows the mind to develop understanding, which can then be followed by wise, loving and wholesome action. Virtue and affection are the hallmarks of this cycle of initiation—the natural propensities of a pure heart, which bestow the power to see and recognise God, the All-Good, and to purify, strengthen and refine the rest of the psyche. 
These two go straight to the center of the island, instead of traveling around it like the others. Ferdinand performs a trial of initiation to demonstrate that he is worthy by obeying Prospero’s command to pile up thousands of logs. Both Miranda and Ferdinand are pure and wise. The culmination of this cycle is their alchemical marriage, from which they will be able to enter the fourth cycle if they choose to do so.
Prospero alone is representative of the fourth cycle, the Adept. He has already transformed himself and learned to master the elements, but he has more work to do in order to benefit others. All laws come from the highest law, the law of love. Stemming from it are the laws of justice and of mercy, and Prospero must learn to reconcile the two. According to Dawkins:
The adept has to learn to operate and reconcile the two seemingly contrary laws, the law of justice (or karma) and the law of mercy (or redemption). The latter is the greater law, but in no way should it, or can it, be used at the expense of justice. Mercy transcends justice and transforms karmic situations into different and more blessed conditions, but it does not replace justice. These two great laws seem like opposites, which they are, yet both are necessary parts of the one supreme law of love. The adept has to learn to operate consciously with both laws, balancing them in perfect harmony. 
Thus, Prospero begins by seeking justice for the wrongs the “bad” lords committed against him. His actions stimulate on Alonso’s part repentance and the desire for forgiveness. In extending mercy and forgiveness, Prospero transmutes Alonso.
It took someone with advanced knowledge about how the cycles of human evolution work to write this play. The Tempest’s author provided an opportunity to those acting in and viewing it to themselves undergo a transformation. At the deepest level, our souls know this. One need look no further for the reason behind the abiding popularity of the Shakespeare plays.
Shakespeare was an adept.
 Peter Dawkins, The Wisdom of Shakespeare in The Tempest (Warwickshire, UK: I. C. Media Productions, 2000), 104.