Mindscape, a must-have podcast by Sean Carroll

Sean Carroll’s Mindscape podcast addresses topics as diverse as the interests of the author, including (but not limited to) physics, biology, philosophy, complexity, intelligence, and consciousness. Carroll has interviewed, in-depth, a large number of very interesting scientists, philosophers, writers, and thinkers, who come to talk about some of the most central open topics in science and philosophy.

Among many other, Daniel Dennett discusses minds and patterns; Max Tegmark  physics, simulation and the multiverse;   António Damásio  feeling, emotions and evolution; Patricia Churchland, conscience and morality; and David Chalmers, the hard problem of consciousness.

In all the interviews, Sean Carroll conducts the conversation in an easy and interactive mode, not imposing his own views, not even on the more controversial topics where the interviewees hold diametrically opposed opinions.

If you are into science and into podcasts, you cannot miss this one.

In the theater of consciousness

Bernard Baars has been one of the few neuroscientists who has dared to face the central problem of consciousness head-on. This 1997 book, which follows his first and most popular book, “A cognitive theory of consciousness”, aims at shedding some light on that most interesting of phenomena, the emergence of conscious reasoning from the workings of atoms and molecules that follow the laws of physics. This book is one of his most relevant works and supports the Global Workspace Theory (GWT), which is one of the few existing alternatives to describe the phenomenon of consciousness (the other one is Integrated Information Theory, IIT).

Baars’ work is probably not as widely known as it deserved, even though he is a famous author and neuroscientist. Unlike several other approaches, by authors as well-known as Daniel Dennett and Douglas Hofstadter, Baars tries to connect actual neuroscience knowledge with what we know about the phenomenon of consciousness.

He does not believe consciousness is an illusion, as several other authors (Dennet and Nørretranders, for instance) have argued. Instead, he argues that specific phenomena that occur in the cortex give rise to consciousness, and provides evidence that such is indeed the case. He argues for a principled approach to study consciousness, treating the phenomenon as a variable, and looking for specific situations that are similar between them but sufficiently different to be diverse in what respects to consciousness.

He proposes a theater metaphor to model the way consciousness arises and provides some evidence that this may be a workable metaphor to understand exactly what goes on in the brain when conscious behavior occurs. He presents evidence from neuroimaging and from specific dysfunctions in the brain that the theater metaphor may, indeed, serve as the basis for the creation of actual conscious, synthetic, systems. This work is today more relevant than ever, as we approach rapidly what can be learned with deep neural networks, which are not only unconscious but also unaware of what they are learning. Further advances in learning and in AI may depend critically on our ability to understand what is consciousness and how it can be used to make the learning of abstract concepts possible.

Do humankind’s best days lie ahead?

This book, which transcribes one of the several Munk debates organized by an initiative financed by Peter and Melanie Munk, addresses the question of whether the future of humanity will be better or worst than the present.

The debate, also available in video, takes place between four formidable names, the wizards Steven Pinker and Matt Ridley (apologists of the theory that technology will continue to bring progress) and the prophets Alain de Botton and Malcolm Gladwell (doubters of the idea that further technological developments will keep improving the world).


The dialogue that takes place, between the Pollyanas and the Cassandras (to use an expression coined in the debate itself) is vivid, interesting and, at times, highly emotional. Not one of the debaters has doubts that progress has improved immensely the human condition in the last few centuries, but the consensus ends with that. Will we be able to use science and technology to surmount the environmental, social, and political challenges faced by humanity or did we already reach “peak development” and the future will be worst than the past? Read or watch the debate, and decide for yourself.

My take is that the Pollyanas, Steven Pinker and Matt Ridley, with their optimistic take on the future, win the debate by a large margin, against the Cassandras, Their arguments that the world will continue to improve, based both on the historical tendencies but also on the hope that technology will solve the significant challenges we face do not meet a coherent resistance from Alain de Botton and Malcolm Gladwell. At least they did not manage to convince me that famines, cybersecurity threats, climate change, and inequality will be enough to reverse the course of human progress.

I am a strange loop – by Douglas Hofstadter

Douglas Hofstadter has always been fond of recursion and self-referential loops, the central topic of his acclaimed “Gödel, Escher and Bach” . In his 2007 book, “I am a strange loop”, Hofstadter goes even deeper into the idea that self-referential loops are the secret item that explains consciousness and self-awareness. The idea that consciousness is the result of our ability to look inside ourselves, and to model our selves in the world, is explored in this book, together with a number of related issues.

To Hofstadter, Gödel theorem, and the way Gödel has shown that any sufficiently complex mathematical system can be used to assert things about itself, is strongly related with our ability to reflect into our own selves, the phenomenon that, according to the author, creates consciousness.

Hofstadter uses the terms “soul” and “consciousness” almost interchangeably, meaning that, to him, our soul and our consciousness – our inner light – are one and the same. Other animals may have souls, such as dogs or cats (but not mosquitoes) although “smaller” and less complex than ours. One of the strongest ideas of the book, much cherished by the author, is that your soul is mostly contained within your brain but is also present, at varying lower levels of fidelity, in the brains of other people that know you and that have models of you inside their own brains.

In the process of describing these ideas, Hofstadter also dispatches with a few “sacred cows”, such as the idea that “zombies” are possible, even in principle, the “inverted spectrum” conundrum (is your red the same as my red?) and the “impossible” – to him- idea of free will.

Machines like me

Ian McEwan´s latest novel, Machines like me does not disappoint if you are looking for a well-written and accurate work of fiction about Artificial Intelligence. The novel takes place in a slightly parallel universe, where Alan Turing did not kill himself and, instead, continued to make important contributions to computer science and to Artificial Intelligence throughout his life. In this world, similar to ours but different in some important respects, AI has evolved much faster and, in the 80s, it became possible to acquire, by a reasonable amount, humanoid robots that could be used as servants, friends or companions.

And, indeed, Adam, the robot, is all of these. From the three characters in the novel (the other two are Charlie and Miranda and yes, there is a sort of love triangle involved) Adam has, no doubt, the more fascinating personality. Without giving away too much, Adam, who starts as something like a sophisticated new laptop, which a 470-page “user manual”, becomes the hero of the story, raising in the mind of the reader many questions about machine intelligence, consciousness, and the rights of intelligent machines. His takes on the events that unfold are sometimes brilliant (e.g., “those who believe in the afterlife will never be disappointed“), other times unexpected,  but never off the mark.

Artificially intelligent or not, Adam is by far the most fascinating character of the lot, and we find ourselves empathizing with him (or it?), in a way that you may not expect

In the process of telling the story, Ian McEwan creates an alternative version of the history of computer science and Artificial Intelligence, which is accurate, thought-provoking, and, ultimately, quite plausible. I strongly recommend this book as an inspiring reading for the summer!

The Fabric of Reality

The Fabric of Reality, a 1997 book by David Deutsch, is full of great ideas, most of them surprising and intriguing. The main argument is that explanations are the centerpiece of science and that four theories play an essential role in our understanding of the world: quantum theory, the theory of evolution, the theory of computation and epistemology (the theory of knowledge).

You may raise a number of questions about these particular choices, such as why is the theory of relativity not there or why is the theory of evolution simply not a result of other theories in physics or even what makes epistemology to special. You will have to read the book to find out but the short answer is that not everything is physics and that theories at many levels are required to explain the world. Still, in physics, the most fundamental idea is quantum theory and it has profound impacts on our understanding of the universe. Perhaps the most significant impact comes from the fact that (according to Deutsch) what we know about quantum theory implies that we live in a multiverse. Each time a quantum phenomenon can conduct to more than one observable result, the universe splits into as many universes as the number of possible results, universes that exist simultaneously in the multiverse.

Although the scientific establishment views the multiverse theory with reservation, to say the least, to Deutsch, the multiverse is not just a theory, but the only possible explanation for what we know about quantum physics (he dismisses the Copenhagen interpretation as nonsense). Armed with these four theories, and the resulting conclusion that we live in a multiverse, Deutsch goes on to address thought-provoking questions, such as:

  • Is life a small thing at the scale of the universe or, on the contrary, is the most important thing on it?
  • Can we have free will, in a deterministic universe? And in the multiverse?
  • Do computers strictly more powerful than Turing machines exist, and how do they work?
  • Can mathematical proofs provide us with absolute certainties about specific mathematical statements?
  • Is time travel possible, at least in principle, either in the physical world or in a virtual reality simulator?
  • Will we (or our descendants, or some other species) eventually become gods, when we reach the Omega point?

The idea of the multiverse is required to answer most, if not all, of these questions. Deutsch is certainly not a parsimonious person when he uses universes to answer questions and to solve problems. The multiverse allows you to have free will, solves the paradoxes of time travel and makes quantum computers possible, among many other things. One example of the generous use of universes made by Deutsch is the following sentence:

When a quantum factorization engine is factorizing a 250-digit number, the number of interfering universes will be of the order of 10 to the 500. This staggeringly large number is the reason why Shor’s algorithm makes factorization tractable. I said that the algorithm requires only a few thousand arithmetic operations. I meant, of course, a few thousand operations in each universe that contributes to the answer. All those computations are performed in parallel, in different universes, and share their results through interference.

The fact that Deutsch’s arguments depend so heavily on the multiverse idea makes this book much more about the multiverse than about the other topics he addresses. After all, if the multiverse theory is wrong, many of Deutsch’s explanations collapse, interesting as they may be.

Still, the book is full of great ideas, makes for some interesting reading, and presents many interesting concepts, some of them further developed in other books by Deutsch, such as The Beginning of Infinity.


Steven Pinker’s latest book, Enlightenment Now, deserves high praise and careful attention, in a world where reason and science are being increasingly threatened. Bill Gates called it “My new favorite book of all time“, which may be somewhat of an exaggeration. Still, the book is, definitely, a must read, and should figure in the top 10 of any reader that believes that science plays an important role in the development of humanity.

Pinker’s main point is that the values of the Enlightenment, which he lists as reason, science, humanism, and progress have not only enabled humanity to evolve immensely since they were adopted, somewhere in the 18th century, but are also our best hope for the future. He argues that these values have not only improved our lives immensely, in the last two and a half centuries, but will also lead us to vastly improved lives in the future. “Dare to understand“, the cry for reason made by David Deutsch in his The Beginning of Infinity, is the key argument made by Pinker in this book. The critical use of reason leads to understanding and understanding leads to progress, unlike the beliefs in myths, religions, miracles, and signs from God(s).  Pinker’s demolition of all the values not based on the critical use of reason is complete and utterly convincing. Do not read this book if, at some level, you believe in things that cannot be explained by reason.

To be fair, a large part of the book is dedicated to showing that progress has, indeed, been remarkable, since the 18th century, when reason and science took hold and replaced myths and religions as the major references for the development of nations and societies. No less than 17 chapters are dedicated to describing the many ways humanity has progressed in the last two and a half centuries, in fields as diverse as health, democracy, wealth, peace and, yes, even sustainability.  Pinker may come up as an incorrigible optimist, describing a world so much better than that which existed in the past, so at odds with the most popular current views that everything is going to the dogs. However, the evidence he presents is compelling, well documented, and discussed at length. Counter-arguments against the idea that progress is true and unstoppable are analyzed in depth and disposed of with style and elegance.

But the book is not only about past progress. In fact, it is mostly about the importance of viewing the Enlightenment values as the only ones that will safeguard a future for humanity. If we want a future, we need to preserve them, in a world where fake news, false science, and radical politics are endangering progress, democracy, and human rights.

It is comforting to find a book that so powerfully defends science, reason, and humanistic values against the claims that only a return to the ways of the past will save humanity of certain doom. Definitely, a must read if you believe in, and care for, Humanity.