Even for large objects, the laws of physics are statistical laws. We have known this since Ludwig Boltzmann's work in 1877. Statistical physics was brilliantly confirmed at the level of atomic collisions by Max Born in 1926, and by Werner Heisenberg in 1927, with his quantum mechanical uncertainty principle. Unfortunately, antipathy to chance led many prominent physicists, then and now, to deny indeterminism and cling to a necessitarian deterministic physics.

Biologists knew even earlier, from Charles Darwin's work in 1859, that chance was the driver for evolution and so chance must be a real part of the universe. Indeed, it is known that quantum collisions of high-energy radiation with the macromolecules carrying genetic information create mutations that are a source of variation in the gene pool.

Charles Sanders Peirce, strongly influenced by Darwin, was the greatest philosopher to embrace chance, and he convinced his friend William James of it. James described the role of chance in free will in his essay, The Dilemma of Determinism.

Information philosophy has identified the cosmic creative processes (we call them "ergodic") that can overcome the chaotic tendency of indeterministic atomic collisions and create macroscopic, information-rich, structures. When these emergent structures are large enough, like the sun and planets, their motions become very well ordered and incredibly stable over time.

DNA has maintained its informational stability for nearly four billion years by adding error detection and correction processes.

Early Greeks like Anaximander saw the universe as a "cosmos" and imagined laws of nature that would explain the cosmos. Later the Stoic physicists identified these laws of nature with laws of God, proclaimed nature to be God, and said both were completely determined.

For the Greeks, the heavens became the paradigm of perfection and orderly repetitive motions without change. The sublunary world was the realm of change and decay. When, two thousand years later, Isaac Newton discovered apparently perfectly accurate dynamical laws of motion for the planets, he seemed to confirm a deterministic universe. But as Newton knew, and as Peirce and later Karl Popper were to argue, we never had observational evidence to support the presumed perfection. The physical laws had become a dogma of determinism.

Why is quantum uncertainty involved in the shaking together (co-agitare) of our agenda items, the real alternative possibilities for thought or action that allow us to say we "could have done otherwise?" There are three important reasons:

• Before quantum uncertainty, many philosophers, mathematicians, and statistical scientists argued that chance was just a name for our ignorance of underlying deterministic processes. They denied the existence of real chance in the universe.

• As soon as quantum mechanics was established in the 1920's, first scientists and then philosophers began claiming that quantum indeterminism could explain free will. We will look briefly at their proposed explanations. After a few years thought, the scientists generally qualified their enthusiasm or reported admissions of failure. Libertarian philosophers have been reluctant to give up on quantum indeterminism.

• Quantum uncertainty remains the best explanation for breaks in the causal chain of strict determinism. But attempts to use the strange non-intuitive aspects of quantum mechanics - such as unpredictable quantum jumps between energy levels, "collapse" of the wave function in physical measurements, non-local behavior of particles that have become "entangled," spontaneous decay of "metastable" states, etc. - as models for the decision process have been hopeless failures. We must identify the critical aspect of quantum mechanical uncertainty that makes an "intelligible" contribution to human freedom while preserving moral responsibility.

Neuroscientists have doubted we could ever locate a randomness generator in the brain. It needs to be small enough to be susceptible to microscopic quantum phenomena, yet capable of affecting the large macromolecular structures like neurons. Let's look at some of the proposals for quantum randomness in the brain.

Probably the first scientist to connect quantum uncertainty to free will was Arthur Stanley Eddington, who until 1927 (in his Gifford Lectures) was a staunch supporter of physical determinism. He then said in 1928 with the "advent of the quantum theory that physics is no longer pledged to a scheme of deterministic law." "We may note that science thereby withdraws its moral opposition to free will."

Eddington's critics accused him of confusing "free" electrons with human freedom. And a decade later, he backed away from quantum randomness as an explanation. He reluctantly concluded there is no "halfway house" between randomness and determinism - an echo of Hume's "no medium betwixt chance and an absolute necessity."

In 1929 Neils Bohr described his views of "complementarity" in the Fundamental Principles underlying the Description of Nature. He applied complementarity to life and organic nature, to mind and body, to subject and object, and, most importantly, to free volition and causality. Although his ideas are vaguely stated, we can see the dialectical reconciling of chance and determinism that goes back to Hegel, James, and Poincaré and forward to Compton, Gomes, Popper, Margenau, and Eccles.

Arthur Holly Compton had shown in 1922 that photons (X-rays) could collide with electrons, showing both matter and radiation had wave-particle properties. In 1931 he proposed that photoelectric cells could work as amplifiers of random quantum events and provide room for human freedom.

Compton's naive model for free will came to be known as the massive switch amplifier. It was open to the ancient criticism that we can not take responsibility for random actions caused by chance. Compton defended the amplifier, but like Eddington, later denied he was trying to show that human freedom was a direct consequence of the uncertainty principle.

If physics were the sole source of our information, he said, we should expect men's actions to follow certain (sic) rules of chance. He said in 1957 that "When one exercises freedom, by his act of choice he is himself adding a factor not supplied by the [random] physical conditions and is thus himself determining what will occur."

Compton was probably a dualist who thought mind was a separate substance. Other scientists who relied on quantum uncertainty to provide alternate possibilities, to be selected among by a non-physical mind, were John Eccles and Henry Margenau.

Our Cogito model simply identifies the source of randomness as the inevitable noise, both thermal noise and quantum noise, that affects both proper storage of information and accurate retrieval of that information at later times. These read/write errors are an appropriately random source of unpredictable new ideas and alternative action possibilities.

We need not look for tiny random-noise generators and amplifiers in specific parts of the brain, any more than the homunculi sometimes evoked by philosophers to parody an internal free agent like a Maxwell's Demon of the mind.

If the Micro Mind is a random generator of frequently outlandish and absurd possibilities (think of the unconscious and the Freudian id), the complementary Macro Mind is a macroscopic structure so large that quantum effects are neglible. This is the critical apparatus that makes predictable - and adequately determined - decisions based on our character and values. Thus we can feel fully responsible for our choices, morally and legally.

Philosophers of Mind, whether hard determinist or compatibilist, should recognize this Macro Mind as everything we need to make a carefully reasoned choice that provides moral responsibility.

But now it is clear that our choices include self-generated random possibilities for thought and action that no external agent, natural or supernatural, and not even ourselves looking internally, can predict.

Our Cogito model gives the determinists what they say they want, an intelligible account of free will in which our decisions are adequately determined, yet completely free and sometimes unpredictable by any external agent and even by ourselves some of the time. We are unpredictably creative.