What is missing from theories of information ?

Theories of information that attempt to sort out problems concerning the status and effi cacy of its content – as it is understood in thoughts, meanings, signs, intended actions, and so forth – have so far failed to resolve a crucial dilemma: how what is represented could possibly have physical consequences. The legacy of this has been played out in various skeptical paradigms that either conclude that content is fundamentally relativistic, holistic, and ungrounded or else is merely epiphenomenal and ineffectual except for its arbitrary correlation with the physical properties of the signs that convey it. In this chapter I argue that the apparent conundrums that make this notion controversial arise because we begin our deliberations with the fallacious assumption that in order for the content of information to have any genuine real world consequences it must have substantial properties, and so must correspond to something present in some form or other. By contrast, I will show that this assumption is invalid and is the ultimate origin of these absurd skeptical consequences. The crucial property of content that must be taken into account is exactly the opposite: its absence. But how is it possible for a specifi c absence to have defi nite causal consequences? A crucial clue is provided by Claude Shannon’s analysis of information in terms of constraint on the entropy (possible variety) of signs/signals (Shannon, 1948; Shannon and Weaver, 1949 ). In other words, the capacity to convey information is dependent on a relationship to something that is specifi cally not produced. But such a change in the Shannon entropy of a physical medium is also necessarily a physical change, and this must be a product of extrinsic work. In addition, contra Shannon, even when there is no change in Shannon entropy where a change is possible, this can be informative because it indicates the absence of some specifi c form of