The Big Picture: On the Origins of Life, Meaning, and the Universe Itself

by Sean Carroll

Purpose and meaning in life arise through fundamentally human acts of creation, rather than being derived from anything outside ourselves. Naturalism is a philosophy of unity and patterns, describing all of reality as a seamless web.

Poetic naturalism is a philosophy of freedom and responsibility. The raw materials of life are given to us by the natural world, and we must work to understand them and accept the consequences. The move from description to prescription, from saying what happens to passing judgment on what should happen, is a creative one, a fundamentally human act. The world is just the world, unfolding according to the patterns of nature, free of any judgmental attributes. The world exists; beauty and goodness are things that we bring to it.

conservation of information implies that each moment contains precisely the right amount of information to determine every other moment.

Principle of Sufficient Reason: For any true fact, there is a reason why it is so, and why something else is not so instead.

When we think about cause and effect, by contrast, we single out certain events as uniquely responsible for events that come afterward, as “making them happen.” That’s not quite how the laws of physics work; events simply are arranged in a certain order, with no special responsibility attributed to one over any of the others. We can’t pick out one moment, or a particular aspect of any one moment, and identify it as “the cause.” Different moments in time in the history of the universe follow each other, according to some pattern, but no one moment causes any other.

Everyone’s entitled to their own priors, but not to their own likelihoods.

the fact that you can come up with an explanation for some event within some theory doesn’t mean that event doesn’t lower the credence you have for the theory.

All evidence matters. It’s not hard to pretend we’re being good Bayesians while we’re actually cooking the books by looking at some evidence but not all of it.

The important takeaway here is that stories can invoke utterly different ideas, and yet accurately describe the same underlying stuff. This will be crucially important down the line. Organisms can be alive even if their constituent atoms are not. Animals can be conscious even if their cells are not. People can make choices even if the very concept of “choice” doesn’t apply to the pieces of which they are made.

One person’s microscopic is another person’s macroscopic.

There tends to be a trade-off between comprehensiveness of a theory and its practicality.

emergence is about different theories speaking different languages, but offering compatible descriptions of the same underlying phenomena in their respective domains of applicability.

The most seductive mistake we can be drawn into when dealing with multiple stories of reality is to mix up vocabularies appropriate to different ways of talking.

You can think of yourself as an individual human being, or you can think of yourself as a collection of atoms. Just not both at the same time, at least when it comes to asking how one kind of thing interacts with another one.

We shouldn’t overestimate people’s rationality or willingness to look at new evidence as objectively as possible. For better or for worse, planets eventually develop highly sophisticated defense mechanisms.

We aspire to be perfect Bayesian abductors, impartially reasoning to the best explanation—but most often we take new data and squeeze it to fit with our preconceptions.

Confirmation bias is our tendency to latch on to and highlight any information that confirms beliefs we already have, while disregarding evidence that may throw our beliefs into question. This tendency is so strong that it leads to the backfire effect—show someone evidence that contradicts what they believe, and studies show that they will usually come away holding their initial belief even more strongly.

We’re faced with the problem that the beliefs we choose to adopt are shaped as much, if not more, by the beliefs we already have than by correspondence with external reality.

Knowing that cognitive biases exist, we can take that fact into account when doing our Bayesian inference. Do you want something to be true? That should count against it in your assignment of credences, not for it. Does new, credible evidence seem incompatible with your worldview? We should give it extra consideration, not toss it aside.

Science never proves anything.

relativity (positions and velocities can be measured only relative to other objects)

Life is short, and certainty never happens.

Science is a technique, not a set of conclusions.

if an ontology predicts almost nothing, it ends up explaining almost nothing, and there’s no reason to believe it.

“Why is there something, rather than nothing?” “If there were nothing,” Morgenbesser immediately replied, “you’d still be complaining.”

Those swirls in the cream mixing into the coffee? That’s us. Ephemeral patterns of complexity, riding a wave of increasing entropy from simple beginnings to a simple end. We should enjoy the ride. 29 Light and Life Italian astronomer Giovanni Schiaparelli will go down in history as the discoverer of the “canals on Mars.”

There is no general principle along the lines of “new kinds of things cannot naturally arise in the course of undirected evolution.” Things like “stars” and “galaxies” come to be in a universe where they formerly didn’t exist. Why not purposes and information?

Here in the early years of the twenty-first century, a majority of philosophers and scientists are naturalists. But in the public sphere, at least in the United States, on questions of morality and meaning, religion and spirituality are given a preeminent place. Our values have not yet caught up to our best ontology.

We don’t need an immovable place to stand; we need to make our peace with a universe that doesn’t care what we do, and take pride in the fact that we care anyway.

The idea of “Ten Commandments” is a deeply compelling one. It combines two impulses that are ingrained in our nature as human beings: making lists of ten things, and telling other people how to behave.