(Copyright © 1999 Piero Scaruffi | Legal restrictions - Termini d'uso )
Daniel Dennett is one of the most prominent philosophers of our time.
The book is about intentionality, about different levels of intentionality and the corresponding different kinds of minds. It rehashes and even reprints a lot of "Darwin's Dangerous Ideas" for a broader audience. (Intentionality is "aboutness", is being about something else, not necessarily in the manner that the English "intentional" word means).
The intentional stance is the strategy of interpreting the behavior of something (a living or non living thing) as if it were a rational agent whose actions are determined by its beliefs and desires. This is the stance we adopt, for example, when dealing with other ourselves and other humans: we assume that we and others are rational agents whose actions are determined by our beliefs and desires. Intentional systems are those to which the intentional stance can be applied, and they include artifacts such as thermostats and computers, and all living beings. We can always think that "this application wants me to input my name" or that "the tree bends south because it needs more light" (both "wants" and "needs" express desire). The intentional stance makes the assumption that an intentional system has goals that it wants to achieve: it uses its beliefs to achieve its goals, and it is smart enough to use the right ones in the appropriate way. Dennett claims that adopting the intentional stance for a broader class of phenomena, not just for humans, helps us both highlight the evolution from our ancestors' foggy consciousness to today's mind and differentiate our mind from the mind of other beings.
It seems obvious that artifacts possess only "derived" intentinality, intentionality that was bestowed on them by their creators. A thermostat measure temperature because that is what the engineer designed it for. The same argument, though, applies to us: we are artifacts of nature and nature bestows on us intentionality (in the Darwinian vision, the process of evolution created our minds to survive in an environment, which means that our mind is about the environment).
Dennett speculates that brains evolved from the slow internal communication systems of "sensitive" but not "sentient" beings when they became equipped with a much swifter communication agent (the electrochemicals of neurotransmitters) in a much swifter communication medium (nerve fibers). This allowed control, that was distributed in order to be able to react faster to external stimuli, to be centralized, as now signals traveled at the speed of electricity. This also allowed control to become much more complicated, as many more things could be done in a second.
"Evolution embodies information in every part of every organism". And that information is about the environment. A chamaleon's skin, a bird's wings, and so forth, they all embody information about the medium in which their bodies live. This information does not need to be replicated in the brain as well. The organ already "knows" how to behave in the environment. Wisdom is not only in the brain, wisdom is embodied as well in the rest of the body. Dennett speculates that this "distributed wisdom" was not enough: a brain can supplement the crudeness, the slowness, the narrowness of the organs. A brain can analyze the environment on a broader scale, can control movement in a much faster way and can predict behavior over a longer range.
As George Miller put it, animals are "informavores". Dennett believes in a distributed information-sucking system, each components of which are constantly fishing for information in the environment. They are all intentional systems, which get organized in a higher-level intentional system, with an "increasing power to produce future".
This idea, both evolutionarily and conceptually, can be represented in a number of steps of intentionality, each of which yields a different kind of mind: "Darwinian creatures", which were simply selected by trial and error on the merits of their bodies' ability to survive; "Skinnerian creatures", which were also capable of independent action and therefore could enhance their chances of survival by finding the best action (conditioning overcame the genetic trial and error of Darwinian creatures); "Popperian creatures", which can play an action internally in a simulated environment before they perform it in the real environment and can therefore reduce the chances of negative effects (information about the environment supplements conditioning); "Gregorian creatures" are tools-enabled, in particular they master the tool of language.
The next step is from beings capable of an intentional stance towards others to beings capable of an intentional stance towards an intentional stance. A first-order intentional system is only capable of an intentional stance towards others. A second-order intentional system is also capable of an intentional stance towards an intentional stance. It has beliefs and desires about beliefs and desires. And so forth. Higher-order intentional system are capable of thoughts like "I want you to believe that I know that you desire a vacation".
This is not yet aware "thinking" as there are examples, both among humans and among other animals, of unaware higher-order intentionality. Animals cheat on each other all the time, and cheating is possible only if you are capable of dealing with the other animal's intentional state (with the other animal's desires and beliefs). One can be a psychologist without being a conscious being.
Drawing from ethology, Dennett reaches the conclusion that thinking arose from inner conversations (self-commentary) which arose from outer conversations (the need to argue with others of the same species) and from the biological need to keep secrets (to secure competitive advantages).
Dennett then claims that our greater intelligence is due not to a larger brain but to the ability to "off load" as much as possible of our cognitive tasks into the environment. We construct "peripheral devices" in the environment to which those tasks can be delegated. In this way the limitations of the brain do not matter anymore, as we have a potentially infinite area of cognitive processing. Most species rely on natural landmarks to find their way around and track food sources. Some species have developed the skills to "create" their own landmark, and they can therefore store food for future use. They are capable of "labeling" the world that they inhabit. Individuals of those species alter the environment and then the altered environment alters their behavior. They create a loop at their advantage, they program the environment to program them.
Species that store and use signs in the environment have an evolutionary advantage because they can "off-load" processing. It is like "taking a note" that we can look up later, so we don't have to remember it. They shape their environment. Their brains are semiotic devices that contain pointers and indices to the external world. Thanks to these artifacts our mind can extend out into the environment.
Language is a self-commentary that begins as labels learned from others. Then we add labels about ourselves.
A mental content becomes conscious by winning the competition with other mental contents and therefore lasting longer in the mind. A mind is an organization of competing mental events.
What makes our thinking different from other species' thinking is that we can obseve our thinking. Other animals may be able to form concepts, but they cannot consider their concepts. We have language that allows us to "think" about our concepts. To Dennett, language is more than just communication: it is a way to unravel the representations in our mind and extract units of them. Without language, an animal may have exactly the same representation, but it doesn't have access to any unit of it. If it can't talk, it can't think.