When trying to understand anything—economies, markets, the weather, whatever—one can approach the subject with two perspectives:

Top down: By trying to find the one code/law that drives them all. For example, in the case of markets, one could study universal laws like supply and demand that affect all economies and markets. In the case of species, one could focus on learning how the genetic code (DNA) works for all species.

Bottom up: By studying each specific case and the codes/laws that are true for them, for example, the codes or laws particular to the market for wheat or the DNA sequences that make ducks different from other species.

Seeing things from the top down is the best way to understand ourselves and the laws of reality within the context of overarching universal laws. That’s not to say it’s not worth having a bottom-up perspective. In fact, to understand the world accurately you need both. By taking a bottom-up perspective that looks at each individual case, we can see how it lines up with our theories about the laws that we expect to govern it. When they line up, we’re good.

By looking at nature from the top down, we can see that much of what we call human nature is really animal nature. That’s because the human brain is programmed with millions of years of genetic learning that we share with other species. Because we share common roots and common laws, we and other animals have similar attributes and constraints. For example, the male/female sexual reproduction process, using two eyes to provide depth perception, and many other systems are shared by many species in the animal kingdom. Similarly, our brains have some “animal” parts that are much older in evolutionary terms than humanity is. These laws that we have in common are the most overarching ones. They wouldn’t be apparent to us if we just looked at ourselves.
