With another election on the horizon in the United States, Americans will soon have to make a familiar decision: liberal or conservative.

Experts will appear on TV arguing about the pros and cons of each side, there will be debate on whether the two-party system is limited, and even more debate on what role the third-parties have to play.

In "Tribe", Sebastian Junger explores this conundrum by looking at our evolutionary history. He argues that since most of our lives as a species was lived in tribes, we are predisposed to want to protect our fellow tribe members. We do this in two ways:

We need to make sure that every one is cared for
We need to make sure that no one is doing anything to harm the tribe

The first need echos a lot of traditional liberal values: government programs, a social safety net, etc. The second need aligns well with traditionally conservative values, such as attention to spending and minimal government interference.

The crucial point is that both needs are important, and both needs are in conflict with each other. We want to look out for others, but we also don't want to be taken advantage of. To force people to choose one side over the other is an impossible choice.

In physics, what's happening in our observable universe is explained by Newtonian mechanics: if an apple falls off a tree it hits the ground, and so on. However, all of these laws completely break down at the sub-atomic level, and for understanding how atoms (and things smaller than atoms) interact, we look to quantum mechanics.

To try to ask which we "prefer" or "think is better", Newtonian or quantum mechanics, doesn't make any sense. They are both correct, but in conflict with each other, and applicable at different times. Similarly, our human needs are both liberal and conservative, and to choose between them doesn't make any sense.

In physics, the dream is to find a theory that unites both Newtonian and quantum mechanics into one elegant unified theory. In politics, perhaps a great unified party will emerge as well, and we'll gladly support it as we board our starships and explore new worlds. But in the meantime, we're stuck with making our familiar liberal-conversative decision.

What we decide will be important. And choosing a candidate and party that aligns with your beliefs is crucial. But it's perhaps important to remember that the decision doesn't define you as a human. We are too complex to be neatly categorized into one end of a spectrum or another. We can embrace conflicting needs at once, and that's okay, because it's in our nature to do so.