Examine the opposition on human nature betweeen Machiavelli and Rousseau.
The difference between Rousseau's and Machiavelli's views on human nature is stark. Rousseau believes that mankind is essentially good. In fact, this view of man is usually contrasted with Thomas Hobbes, who asserted that mankind was self-serving and depraved, driven to take from others in pursuit of self-preservation. Speaking of man in his natural state, Rousseau observes:
Such is the pure emotion of nature, prior to all kinds of reflection! Such is the force of natural compassion, which the greatest depravity of morals has as yet hardly been able to destroy!
Rousseau argues that it is the trappings of so-called civilization that have corrupted man, and created a need for government. Men, in short, were innately good and decent, and were corrupted by their entrance into society.
Rousseau is a idealist and a theorist, but Machiavelli, at least in writing The Prince, is a hard-nosed pragmatist. He is less interested in how man became corrupted than in showing that rulers ought to deal with men as they are, not as they were or should be. His view of human nature is accordingly pretty bleak:
Because this is to be asserted in general of men, that they are ungrateful, fickle, false, cowardly, covetous, and as long as you succeed they are yours entirely; they will offer you their blood, property, life and children, as is said above, when the need is far distant; but when it approaches they turn against you.
Machiavelli emphasized the need for a prince to be every bit as duplicitous as his subjects in order to rule them. They had to behave as tyrants, if necessary. Rousseau, on the other hand, posited that the best government would be one that ruled based on the "general will" of the people. So their very different views on human nature deeply informed their views of how people must be governed.
At its core, Rousseau's idea of human nature is an optimistic one. He sees human nature as intrinsically good when it gets away from social attachments and the corrupting influence of society. For Rousseau, human nature is a good impulse where the best of human beings are displayed. Rousseau's political theory is rooted in this idea of getting human beings into a social setting that is devoid of the corrupting elements of society. Rousseau's pivot towards a political and social order of amour propre over amour de soi is evidence of this.
The innate goodness of human nature that Rousseau sees as part of humanity is not something that Machiavelli shares. Machiavelli saw human nature as duplicitous. He was not suggesting that humans are evil, as much as they need to display different elements in different contexts in order to achieve what they want. There is a relativism that lies at the core of human nature, for everything is contingent on circumstance and condition. Human nature reflects this. For Machiavelli, politics was designed to engage in such manipulation. Morality and goodness were secondary to the political expedience of such elements. Rousseau believed that human nature was essential to the political experience to reflect intrinsic goodness. Machiavelli sees human nature as something contingent and conditional, able to show malleability in a political climate that nets the best result for those in the position of power.