Shakespeare's The Tempest, although a fictional product of the playwright's imagination, contains deep and varied allegories that explore the nature of power and the qualities of a ruler. These are concepts that Shakespeare returned to again and again in his plays—kings gone mad, rulers usurping other rulers, and the constant plotting of one group against another to seize power.
John Locke and Thomas Hobbes, two other Englishmen who became prominent in the 1600s, just after Shakespeare's time, were equally fascinated by these questions. As philosophers, rather than playwrights, they attempted to address the nature of power and the social organization of humankind through argument and study, and came to have influential theories about politics and human nature.
Hobbes is best known for his belief that, left to their own devices, individual people with no government resort to a merciless free-for-all. In the "state of nature," what he believed was the original human condition, power and violence was the governing principle of human life. This idea led him to a belief in strong centralized power.
Locke, on the other hand, is known as the father of modern liberalism. He wrote that in a state of nature, all men are created equally, and have certain natural rights. When men enter into a social contract, it is not out of fear, as Hobbes would say, but out of a desire to organize civil life more productively. It is from this understanding of human nature that Locke decried the divine right of kings, as a source of power that has no place in human governance.
Scenes and characters in The Tempest show that Shakespeare is working out the same underlying questions that would later fascinate Hobbes and Locke. The incessant scheming and plotting, not only by Prospero but by his brother, Antonio, and the King's son Sebastian, and many other parties, seem to demonstrate Hobbes' belief that power is only acquired through strong power, rather than through reason or divine right. However, Prospero's scheming reveals a fairness and decency that is surprising from an all-powerful sorcerer, and his triumph over the myriad plots against him, with relatively little ill-will could be seen as more in line with Locke's thinking about the fundamental decency of people.
Complicating these ideas, though, is the historical context. Shakespeare, Locke and Hobbes were all living in a time of profound colonial unrest, as new colonies in America shifted the balance of the world and produced unsettling thoughts about human nature. The slave character, Caliban, in particular has been re-examined as an allusion to slavery in the New World, and his untouched island eden may also have been a reference to colonial reports from the Caribbean and elsewhere. Likewise, Hobbes and Locke both based their ideas of "the state of nature" on what they imagined to be the conditions in the New World, and many of their ideas about early human life came from shallow understandings of Native American cultures.
In these ways, The Tempest can be read from many different perspectives, and shows that Shakespeare was grappling with many of the same questions about power and rulers that has fascinated philosophers and politicians for millennia.