Lloyd's most provocative idea is that the universe is a giant computer. Everything in it, including all living systems, are running one enormous program. This seems to be an extreme form of determinism, with the program an example of the super-intelligence of a Laplace Demon, who can see the complete past and future. But Lloyd is no determinist, he sees that quantum mechanics introduces probabilities and uncertainty.

Lloyd worked with Rolf Landauer at IBM, who extended the ideas of John von Neumann and Leo Szilard, who, along with many other physicists, had connected a physical measurement with thermodynamical irreversibility, that is to say a dissipation of energy and increase in entropy.

The increase in entropy (or decrease in available negentropy, as Leon Brillouin put it), must equal or exceed the increase in information acquired in the measurement, in order to satisfy the second law of thermodynamics. There is an intimate connection of physical things and information, captured in John Wheeler's famous dictum, "It from bit."

Seth Lloyd is quite correct that information ("bits") is physical ("its"). However, unlike things, which are concrete and material. Information is abstract and immaterial. To be sure, bits in a computer are embodied in the logical switches that represent 1's and 0's.

By contrast, he says that the theory of computation provides an "intrinsic computational unpredictability" that gives "rise to our impression that we possess free will."

Unpredictability is not freedom, just the inability for anyone, including ourselves, to predict what we are going to do.

Lloyd writes,

The primary scientific issue in the debate over free will is traditionally taken to be the question of whether the world is deterministic or probabilistic in nature . (Whether or not this is indeed the proper question to ask will be discussed in detail below.) In a deterministic world, events in the past fully determine the outcomes of all events in the present and future. Conversely, if the world is probabilistic, then at least some outcomes of current events are neither determined nor caused by events in the past. Determinism is evidently a problem for free will: more than two thousand years ago, Epicurus felt obliged to emend the determinism of Democritus’s atomic picture by adding an occasional probabilistic ‘swerve’ to the motion of atoms, in part to preserve freedom of will. From the seventeenth until the twentieth century, by contrast, most scientists believed that the world was deterministic, for the simple reason that all known physical laws, from Newton’s laws to Maxwell’s equations, were expressed in terms of deterministic differential equations. In such theories, apparently probabilistic behavior arises from lack of knowledge combined with sensitive dependence on initial conditions (‘chaos’) [2]. In a deterministic physical world, an hypothetical being (Laplace’s ‘demon’) that possesses exact knowledge of the past could in principle use the laws of physics to predict the entire future.

From Newton up to the twentieth century, the philosophical debate over free will by and large assumed that the world is deterministic. In such a deterministic world, there are two antagonistic philosophical positions [3]. Incompatibilism claims that free will is incompatible with a deterministic world: since all events, including our decisions, were determined long ago, there is no space for freedom in our choices. Compatibilism, by contrast, asserts that free will is compatible with a derministic world. In contrast to classical mechanics, the theory of quantum mechanics that emerged as the fundamental physical framework at the beginning of the twentieth cnetury predicts that the world is intrinsically probabilistic. Despite Einstein’s opinion that ‘God does not play dice,’ experiment and theory have repeatedly confirmed the probabilistic nature of events in quantum mechanics. For example, the Kochen-Specher theorem [18] shows that certain types of deterministic hidden-variable theories are incompatible with the predictions of quantum mechanics, a result extended by the Conway-Kochen ‘free will theorem’ [19]. (Despite the presence of the phrase ‘free will’ in its title, and the authors’ whimsical assertion that ‘if indeed we humans have free will, then elementary particles already have their own small share of this valuable commodity,’ this theorem is less a statement about free will in the sense discussed in the current paper, and more a statement about the incompatibility of deterministic models of quantum mechanics with special relativity.) At first, it might seem that the probabilistic nature of the underlying physics of the universe implies renders the compatibilism–incompatibilism debate moot. Indeed, when it became clear starting in the mid-nineteen twenties that quantum mechanics was necessarily probabilistic, scientists began to invoke the probabilistic nature of quantum mechanics to supply the freedom in free will. In 1928 Arthur Eddington stated [4] that with the ‘advent of the quantum theory . . . physics is no longer pledged to a scheme of deterministic law.’ Consequently, ‘science thereby withdraws its moral opposition to free will.’ Eddington’s book inspired Turing to investigate the connection between quantum mechanics and free will [1]. The way in which quantum mechanics injects chance into the world was analyzed by A.H. Compton [5], whose work on photo-electric cells formed the basis for his notion of a ‘massive switch amplifier’ that could amplify tiny quantum fluctuations to at scale accessible to the brain. Such purely random information resulting from the amplification of quantum fluctuations, Eddington and Compton argued, could then supply the seeds for probabilistic decisions. The Conway-Kochen theorem is the latest in a long line of works that identifies free will with the probabilistic nature of quantum mechanics.

But are decisions ‘free’ simply because they are probabilistic? Flipping a coin to make a decision is typically used as a last resort by deciders who are unable to make the decision themselves: the outcome of the coin toss determines the decision, not you. As the twentieth century wended on, it became clear that merely adding randomness did not obvously solve the problem posed by incompatibilism. After all, as the philosopher Karl Popper noted [6], one of they key features of a decision arrived at by the process of free will is that it is NOT random. Eddington and Compton backtracked. By the end of the twentieth century, Steven Pinker could declare confidently [7] that ‘a random event does not fit the concept of free will any more than a lawful one does.’ If determinism robs us of agency, then so does randomness.

For many contemporary scientific opponents of free will, it seems that the problem with free will is not so much the question of determinism vs. probability, but rather the existence of a mechanistic description of the system that is making the decision.

(A Turing Test for Free Will, pp.3-5)

Naturalism is a materialism, indeed an eliminative materialism. This is the idea that there are no ideas and no minds. The immaterial mind is identical to the material brain.

Philosophers who have attempted to explain free will in terms of event causation (for example, Robert Kane, assume that everything is the result of a causal chain of events, some of which are determined, others are probabilistic, uncaused, or "self-caused."

There is nowhere in this picture for a mind that can generate alternative possibilities for action and then evaluate all those possibilities, holding them all in a mind before a deliberation process evaluates them all and selects one. This is the two-stage model of free will.

Lloyd is a member of a group of scientists and philosophers pursuing "digital philosophy," They include Gregory Chaitin, Edward Fredkin, Rudy Rucker, Jürgen Schmidhuber, Stephen Wolfram, and Konrad Zuse.