
Clare P. answered 10/02/19
Published Philosoper with 30 Years Experience
You should remember that the state of nature, for Hobbes, simply means we lack a governmental authority who can make and enforce rules. In other words, we are each on our own, able to depend only on ourselves.
Hobbes begins with an extensive set of assumptions & argument about the mental and psychological workings of human beings, as animals, understood only through observation and science. He insists that human beings are not inherently social animals (like bees or ants, or even like pack animals ands herd animals), but are instead competitive individuals. He claims we are sociable under governments because we are compelled to be and not because we necessarily enjoy it. He also claims: that we are effectively equal to others both in physical power and in practical judgement. This is because none of us can be physically powerful enough or smart enough to guarantee that we are safe from being killed by others (so we're all equally vulnerable, thus effectively physically equal), and we are also all satisfied with our own level of understanding and don't consider others to be better at judging and choosing than we are. Because of this equality, we never have any reason to think we have any less a chance of getting what we want if we try than others do. In other words, we aren't inclined to hold off doing anything that we want out of fear of failing or being caught or hurt.
On top of thinking we are equally able to decide what we want and go after it successfully, we have three qualities that make us likely to fight: we are competitive (and so greedy- we want to be and have better than others around us); we fear for our safety & distrust others around us; and we are full of ourselves, always concerned about our reputation and whether or not others give us as much respect as we believe we deserve (and since we always believe we deserve more than we actually do, we are prone to think others are showing disrespect and to get angry about it).
These qualities make us warlike: we are likely to attack others to take what belongs to them or to show we are stronger or better; we are likely to fight others because we think they are a threat to us or might be a threat in the future; and we are also likely to fight with others because we feel injured when we think they fail to treat us with proper respect (which is often). At the same time, because he argues that we are not naturally social animals, we don't have any of the curbs on aggression that come with natural sociability.
Based on this description, we have plenty of reasons to fight with and kill others, and no reason to stop. Others as having what we want, they threaten us, and they treat us unjustly and disrespectfully, while we don't think we are any more likely to lose (so that doesn't hold us back), and we don't have any natural love for others or sense of duty (so those things don't hold us back either). We can't help but see ourselves as surrounded by current or future enemies.
In that situation, it makes sense to try to get as much wealth as we can, to control as much territory as we can, to have as many allies and armies as we can; to use every way we can to fight or cheat our way into wealth and physical strength (territory and armies) and take those away from others makes us safer. So we enter into aggressive wars a lot, and so do others (who think the same way). And even when we might have some peace, we have to be aware that we are constantly vulnerable, and so it makes good sense to pre-emptively attack anyone who might become strong enough to threaten us. This is the case whether they threaten us from the outside by attack or from the inside by treachery & disloyalty. Since we're not naturally social, so we have no reason to expect others not to betray us when it suits them, or to hold ourselves back from, say, poisoning a rich or powerful person when we have the chance to get away with it. We constantly offend each other and make each other angry.
If you add these things together, and also remember that no government (nature) means no laws that can constrain us and no power to stop us, then a simple state of nature would naturally and quickly evolve into a society of constantly battling warlords who are always plotting and being plotted against. We would be constantly in a state of either physical war or of mental war (preparing for physical war). If this is the case, then the real question is, why wouldn't we kill each other? It's a choice between "kill or be killed" and "come together and create a government which can control us & put a stop to that." Based on Hobbes' assumptions about human nature, his conclusions are only logical.
Of course, Rousseau counters this with the argument that Hobbes' assumptions about human beings in the state of nature are wrong because he fails to see how living under government changes us (or in general how what we are evolves and transforms depending on the conditions). This is really the only opening Hobbes leaves us-- to challenge his assumptions.