The Universe has been around for 13.8 billion years; humans for just 200,000 years, or just 1/69,000th of the age of the Universe. Less than 100 years ago, humans created machines that can do fancy calculations on their own. To put thinking machines in their context we need to think about the history of thinking.
Thinking, and thinking in more and more complex ways, are phenomena that belong to a larger story, the story of how our universe has created more and more complex networks of things, glued together by energy, and each with new emergent properties. Stars are structured clouds of protons; the energy of fusion holds the networks together. When large stars shattered in supernovae, creating new types of atoms, electromagnetism pulled the atoms into networks of ice and silica dust, and gravity pulled molecules into the vast chemical networks we call planets. Thinking arises within the even more complex networks formed by living organisms. Unlike complex things that live close to equilibrium, such as stars or crystals, living organisms have to survive in unstable environments. They swim through constantly shifting gradients of acidity, temperature, pressure, heat and so on. So they have to constantly adjust. We call this constant adjustment "homeostasis", and it's what creates the feeling that living organisms have purpose and the ability to choose. In short, they seem to think. They can choose from alternatives so as to ensure they manage enough energy to keep going. This means that their choices are not at all random. On the contrary, natural selection ensures that most of the time most organisms will go for the alternatives that enhance their chances of controlling the energy and resources they need to survive and reproduce.
Neurons are fancy cells that are good at making choices. They can also network to form brains. A few neurons can make a few choices, but the number of possible choices rises exponentially as neuronal networks expand. So does the subtlety of the decisions brains make about their surroundings. As organisms got more complex, cells networked to create towering organic structures, the biological equivalents of the Empire State Building or the Burj Khalifa. The neurons in their brains created ever more elaborate networks, so they could steer lumbering bodies in extraordinarily subtle and creative ways to ensure the bodies could survive and reproduce more bodies. Above all, brains had to ensure their bodies could tap flows of energy through the biosphere, flows that derived from energy produced by fusion in our sun and then captured through photosynthesis.
Humans added one more level of networking, as human language linked brains across regions and generations to create vast regional thinking networks. This is "collective learning". Its power has increased as humans have networked more and more efficiently, in larger and larger communities, and learned how to tap larger flows of biospheric energy. In the last 200 years, the networks have become global and we have learned to tap vast stores of fossilized sunlight buried over 300 million years. This is why our impact on the biosphere is so colossal in the Anthropocene Epoch.
Collective learning has also delivered thinking prosthetics from stories to writing to printing to science. Each has cranked up the power of this fantastic thinking machine made from networked human brains. But in the last 100 years the combination of fossil fuels and non-human computers has cranked it up faster than ever before. As computers forged their own networks in the last 30 years, their prosthetic power has magnified the collective power of human thinking many times over.
Today the most powerful thinking machine we know of has been cobbled together from billions of human brains, each built from vast networks of neurons, then networked through space and time, and now supercharged by millions of networked computers.
Is anyone in charge of this thing? Does anything hold it together? If so, who does it serve and what does it want? If no one's in charge, does this mean that nothing is really steering the colossus of modern society? That's scarey! What worries me most is not what this vast machine is thinking, but whether there is any coherence to its thinking. Or will all its different parts pull in different directions until it breaks down, with catastrophic consequences for our children's children?