What is Abstraction anyway: Part Two

The Super Power of Abstraction

1. Where we left off

In Part One, we used leaves to show what abstraction is: we took the same method, applied it to different objects, and got strikingly similar results. That was abstraction — a way of finding what is common.

But abstraction is more than a neat trick. It has a hidden power. In this part, we dig into how that power was born — not in a math classroom, but out of everyday life: a hunt, and a trade.

2. The hunt

Imagine a small tribe living in the forest. Every day, the same problem returns: where is the food, and how many people should go get it?

At first, the whole tribe went out together, searching in one direction. But one direction means a small space. So the tribe changed the plan.

They split into small groups. Each group went a different way. Suddenly, their search space multiplied — five small teams could cover five different directions instead of everyone crowding one path.

When each group came back, they brought back more than meat. They brought back two things: a number and a direction.

"There is a herd of deer to the northeast, about a day away."
"There are wild ducks by the southern river."

Each report was really a vector — a quantity and a direction tied together.

Now the leader could do something new. Instead of guessing, they could compare the reports: this direction has more game and is farther, so send more people; that direction has little game and is near, so send fewer.

The vector pointed the way, and it decided how many hands to send. The hunt was no longer a guess. Spread the search, decide together, catch the prey — and the payoff multiplied.

3. The super power of abstraction

Look at what happened. The tribe did not invent a magic weapon. They did one simple thing: they pulled the "how many" and the "which way" out of the actual deer and ducks, and turned them into symbols that could be compared and counted.

That is the super power of abstraction. It lets you take a messy, particular situation and boil it down to something you can reuse, compare, and decide with. A number without the deer. A direction without the walking. Combined, they become a tool for thinking.

Once the tribe had this power, they could use it again and again — for the next hunt, and the one after.

4. The trade

Now imagine the tribe by the river, where two peoples meet. One raises cattle, the other keeps sheep. They cannot eat each other's food until they agree on a way to trade.

So they agree on a rule:

One cow is worth five sheep.

That little rule is a function. Write it as f(cow) = 5 sheep. It does not care about this particular cow or that particular sheep — it is a dependence between two kinds of things, a rule you can reuse all day, every day.

But here is the real magic. The function can compose.

Tomorrow they meet a third people who grow wheat, and they agree: five sheep are worth two sacks of wheat. Write it as g(sheep) = 2 wheat.

Now, without any negotiation, the first people already know:

f(g(sheep)) = 10 wheat, for the same five sheep.

They never touched the wheat, never haggled, and yet they can already convert their cows into wheat. Each new rule in the market layers onto the old ones, and the whole village's ability to trade multiplies.

Carry this far enough, and the layers of functions begin to point at one thing everyone can measure against — and that, in time, is the seed of money. Money is just the universal function that maps everything onto one common scale.

The trade did not invent a coin. It invented a rule for changing one thing into another — and that rule, reused and composed, is what moves an economy.

5. Where it came from

So the two great powers of mathematics — the quantity behind numbers and vectors, and the correspondence behind functions — were not born in a classroom.

They came from ordinary life. A hunt taught people to pull out "how many" and "which way." A trade taught people to pull out "a rule that changes one thing into another."

Any time, anywhere — abstraction was already working, long before anyone gave it a name.

Think about it: can you find another example like this in your own life?