Plato describes the visible world of perceived physical objects and the images we make of them (in our minds and in our drawings, for example). The sun, he said, not only provides the visibility of the objects, but also generates them and is the source of their growth and nurture. Many primitive religions identify the sun with God, for good reason.

Beyond this visible world, which later philosophers (esp. Immanuel Kant) would call the phenomenal world, lies an intelligible world (that Kant calls noumenal). The intelligible world is (metaphorically) illuminated by "the Good" (τον ἀγαθὸν), just as the visible world is illuminated by the sun.

Plato's Line is also a division between Body and Mind. The upper half of the divided line is usually called Intelligible as opposed to Visible, meaning that it is "seen" by the mind (510E). Illuminated by "the Good," it is seen by the Greek Nous (νοῦς), rather than by the eye.

The division of Plato's Line between Visible and Intelligible is then a divide between the Material and the Ideal, the foundation of most Dualisms. Plato may have coined the word "idea" (ἰδέα), using it somewhat interchangeably with the Greek word for shape or form (εἶδος). The word idea derives from past participle in Greek for "to have seen."

In many ways, Plato's theory of immaterial forms existing outside space and time and providing the shape of material things is consonant with information philosophy's focus on immaterial information as the basis for thought, for mind, for knowledge, and for the abstractable elements of information structures in the real world. Plato's distinction between Form and Matter stands at the beginning of the great dualism between Idealism and Materialism.

Information philosophy is a return to a kind of Idealism. It situates the Good in the Platonic realm of Ideas, which we now recognize as immaterial information. And it shows how immaterial ideas can have causal force in the world of matter and energy, solving the Mind-Body problem, among others.

Now the Good in an information structure such as a material thing, a living thing, or a complex situation including many things, can in principle be calculated as the quantitative amount of negative entropy that it contains. Perhaps it is equally easy to see the Bad in something by measuring its destructive force. Think of the evil in a thermonuclear weapon, whose only use is to destroy a city and its population.

But it is plain that no single monotonic value can decide between the goodness of two things, since values are deeply context dependent. Indeed, Kenneth Arrow's theorem in economics shows that values are not strictly transitive. A can be preferred to B, B preferred to C, and yet C can be preferred to A.

Nevertheless, however imperfect it may be, information, or more generally negative entropy, provides an objective, human-independent, starting point for comparisons, without which all preferences are hopelessly subjective and relative to the individual or to the society. This is as it should be. Facts of the matter are questions for science. What should be or ought to be are cultural question for society or individual persons.

Free will is a scientific question. Moral responsibility is a cultural and conventional question for society. Nevertheless, those answering the conventional questions of right and wrong can consult the informational and entropic implications of different choices.

Consider utilitarianism, which hopes to achieve the "greatest good for the greatest number." The measure of utility in something correlates strongly with the amount of free or available energy (negative entropy) in that thing.

The unavoidable Second Law of Thermodynamics, teh Entropy Law, has been confirmed in the kinetic theory of gases by Ludwig Boltzmann with his H-Theorem, and in statistical mechanics and quantum mechanics by Albert Einstein with his analysis of fluctuations in the entropy.

As the universe evolves, the increase in the total entropy, the disorder and chaos, is unstoppable. Fortunately, there are important places where the entropy is reduced locally, leaving behind information structures, pockets of negative entropy or cosmos.

The established fact of increasing entropy led many scientists and philosophers to assume that the universe we have is "running down" to a "heat death." They think that means the universe began in a very high state of information, since the second law requires that any organization or order is susceptible to decay. The information that remains today, in their view, has always been here. There is "nothing new under the sun."

But the universe is not a closed system. It is in a dynamic state of expansion that is moving away from thermodynamic equilibrium faster than entropic processes can keep up. The maximum possible entropy is increasing much faster than the actual increase in entropy. The difference between the maximum possible entropy and the actual entropy is potential information.

Creation of information structures means that in parts of the universe the local entropy is actually going down. Our Sun-Earth system is one such place. All life depends on the flow of negative entropy from Sun to Earth. Creation of a low entropy system (the Good) is always accompanied by radiation of entropy (the Bad) away from the local structures to distant parts of the universe, into the night sky for example and away through our transparent universe to the most distant cosmic microwave background.