Human nature refers to the characteristics and underlying attitudes shared by all humans. That being said, what that may be has varied and changed over the ages. In the classical conception of it, Aristotle described humans to be, by nature, political animals whose purpose is to attain and maintain their highest good. In order to do that, however, one must live well with others because in living with others one attains virtues such as justice or prudence. Some more modern thinkers like Machiavelli, Bacon, and Hobbes were in violent disagreement. This is mainly due to the Aristotelian idea that the wise were the best suited to rule over the many. In addition to that, the modern thinkers had an immensely different definition as to what human nature was. They thought human nature was based off of the self-serving desire to preserve their life at all costs.
Of the three modernists, Machiavelli is perhaps the most strategic in his explanations because he relates human nature in regards to how they might be ruled or conquered by principalities; whereas Hobbes describes human nature in greater detail in relation to a hypothetical situation called the state of nature. Both agree in the idea that humans are self-serving and self-interested, yet for Hobbes, this means that men will jump into a state of conflict and war because they assume that if they do not that their opponent surely will. Although Machiavelli does not explicitly define human nature, like Hobbes does, he does give several implications as to how human beings typically act when he addresses political rule. Machiavelli, to begin with, acknowledges that the passions of human beings are frequently changing and never satiable. He states, "the nature of peoples is variable; and it is easy to persuade them of something, but difficult to keep them in that persuasion. And thus things must be ordered in such a mode that when they no longer believe, no one can make them believe by force" (Machiavelli 24). Machiavelli, in contrast to Hobbes, is more willing to consider the possibility that humans are more likely to act out of mutual self-interest and be swayed into being the subjects of Princes instead of doubtfully picking each other off in fear. Therefore, Machiavelli advises that fear be instilled in the principality which could be further utilized to unify the citizens and secure the nation. Hobbes, too, sees the necessity of a regime but where he differs is in its purpose; he thinks that the purpose of a regime is to keep its subjects, the people, from attacking each other and that, further, people are in contracts with each other--not the state. Machiavelli asserts that, "it is a very natural and ordinary thing to desire to acquire, and always, when men do it who can, they will be praised or not blamed; but when they cannot, and wish to do it anyway, here lie the error and the blame." (Machiavelli 14). Machiavelli suggests that it is the nature of mankind to want to have things and further to desire to keep what they have attained for as long as they can. This, of course, would be to the state's advantage because it suggests that the people's affection can be both won and lost in accordance to the possession of material things.
Bacon's New Atlantis tells a tale of a utopian society which is governed by a few wise scientists that have essentially gained the power to control and manipulate nature through the use of science. Further, this community utilizes the powers of science to make its citizens believe in the irrationality of their religion, Christianity. They assume that if science can have the appearance of demonstrating evidence, then their beliefs must hold to be true and its citizens would have no cause to revolt. The irony of that is, that they have an institution called Solomon's House whose sole purpose is devoted to the study of nature. "The End of our Foundation is the knowledge of Causes, and secret motions of things; and the enlarging of the bounds of Human Empire, to the effecting of all things possible." (Bacon 71). The organization is armed, in a certain sense, with pieces of natural knowledge which, again, they manage to best suit the ideals that hold their society secure and its laws in place. Bacon's take on human nature, much like Machiavelli's, is not defined clearly but it's implications are produced by its citizens. This society is structured in such a way that people are almost urged to pursue their base desires. For instance, in the Adam and Eve pools friends of both genders are permitted to see their friend's potential partner naked to check for any defects (Bacon 68). Though polygamy was strictly forbidden in Bensalem the idea that if done in the right manner, cloaked in Christian purity, this type of behavior wasn't looked down upon. For Bacon, the necessity of religion was a direct cause from the inability to reduce human nature to a rational explanation. He thought the human mind, much like human bodies, were always subject to defect and thus were prone to belief.
Hobbes gives the most comprehensible outlook on human nature of the three, since he offers concrete, tangible explanations in Leviathan. He begins by describing the human body as it is: an external object whose organs are proper to sense. (Hobbes, 1). The senses, Hobbes claims, humans exercise to maneuver and interact within the world. He brings the concept down to a very basic understanding of the human person--as a physical body. In this sense, he was in disagreement with the ancients who prescribed vague ideas to aspects of ourselves such as the soul or virtue. Since humans utilize the senses, it is natural for them to respond accordingly to both pain and pleasure. Hobbes demonstrates that by suggesting that what delights our senses we call pleasure and are inclined towards; and what we dislike or what hurts us we move away from. He regards human nature to be something quite animalistic. Bacon, in this regard is comparable to Hobbes because to Bacon a comfortable physical life is filled with sensible pleasures which directly leads to a fulfilled spiritual life. However, where the two differ is that Hobbes takes a more pessimistic approach towards appetites. He writes, "I put for a generall inclination of all mankind, a perpetuall and restlesse desire of Power after power, that ceaseth onely in Death"(Hobbes 59). According to Hobbes, it is the fear of death that causes men to long for peace and in this manner Hobbes agrees with the Machiavelli's idea that people are selfish and are only interested in acquiring their desires which causes them to always want more. The rationalization is that the reason human beings are in always in conflict with one another in the absence of a regime is due to everyone thinking they are obligated and entitled to things--thus they quarrel. Hobbes expresses, "Hereby it is manifest, that during the time men live without a common Power to keep them all in awe, they are in that condition which is called Warre; and such a warre, as is of every man, against every man" (Hobbes 77). To Hobbes, a contract and forfeit of some of their rights to a regime is necessity to keep the people from killing each other off both out of fear of death and the desire to preserve themselves. "The Right of Nature is the Liberty each man hath, to use his own power, as he will himselfe, for the preservation of his own Nature; that is to say, of his own Life" (Hobbes 79). The desire for self-preservation and survival is a passion that all humans possess and as a result Hobbes says the way to make this occur without so much uncertainty is by having a sovereign state hold the powers of the people and by doing so forcing them to enter into a contract with each other.
Although these thinkers varied on particular aspects of their philosophies, they generally agreed on the idea that, primarily, humans nature is based off of the self-serving desire and interest to preserve their life at all costs. Machiavelli used strategic in his depiction of human behavior, while Bacon utilize belief to describe human nature. Hobbes on the other hand, demonstrated that humans are by nature individuals who are isolated in their state of nature.