Colbert's "Truthiness" is very much the little word that could, at least for the past couple years, and in the eyes of dictionary and news people. Truthiness has successfully brought a timeless philosophical topic, the issue of how truth is defined, into wide-reaching public awareness. I also consider it a symptom of one of the marks of a healthy/free society: debates not only about specific issues and questions but also paradigms and assumptions. However, the simple use of truthiness as a term of mockery overlooks several deep, thorny points. The following explanation will be reminiscent of what I wrote about truth and wikipedia.
As I understand it, truthiness means arriving at truth subjectively as opposed to objectively. The opposite of truthiness is only granting truth to the objective realm. Naturally, dividing up the world into two neat chunks of objective truth and subjective falsehood is nothing new; see Hume and Positivism and so on. It has also been a popular thing to argue about. Keeping in mind that I'm considering one lil' concept here, and not a robust philosophy, here are some indications that it is not all-sufficient:
- Objective truth is deniable. I covered this point in the post about wikipedia. I don't mean that evidence is worthless. I do mean that evidence can be disputed - in fact, the strength of an item of evidence is how well it stands up to dispute. Conflicting evidence and the method of measurement are just two avenues of attack. This isn't a compelling downside, since almost all statements are deniable somehow (even if in some cases those denials would mark someone as clinically insane). I mention it merely as a reminder that if Alice and Bob are talking about Eve, and Alice refers to evidence from Carol, Bob can counter Alice by smack-talking about Carol's evidence-gathering abilities. On the other hand, many people can vet objective truth, so only the foolish would casually ignore it. And if someone is almost alone in denial, then he or she is likely mistaken.
- Not all truth is objective. Some statements can't be evaluated objectively, but nevertheless have a definite truth value. Intuitions about someone else's state of mind fall into this category. And some people are correct far too often in order for this facility to be considered wild guessing. Sometimes the mind can extrapolate a large conclusion from an assortment of tiny, fuzzy data points - a process known as induction or gestalt reasoning. None of the individual signs would constitute conclusive proof, but taken together the case is strong. This truth is not achieved objectively but subjectively, because the mind of the observer plays such an important role that no two people would reach the same truth given the same data. Intuitions may be true or false just like any other statement, or half-true or mostly-false. One need only look at an optical illusion to realize that intuitive truth has its own weaknesses, however.
- Consciousness exists but is not objective by definition. All philosophers, regardless of their opinions about the definition of truth, admit that thoughts and emotions have some degree of reality. In other words, the subjective realm exists, and therefore statements related to it can be true or false. If someone says he or she dreamed about yellow matter custard dripping from a dead dog's eye, no one else can evaluate the truth value of that statement, but the statement has a truth value because the dreamer can dream. To put it another way, suppose that someone created the ultimate android, an artificial lifeform that mimicked a person exactly. Could we determine if the android had consciousness? "Sure", you might say. "Just ask it about its consciousness." But if the android mimicked consciousness precisely, we could never know for sure. After all, we couldn't disassemble it to find its consciousness, no more than we can dice a brain and locate consciousness. Yet human consciousness exists, apart from objective truth.
- The objective and subjective realms are not cleanly separated. I've been writing under the unstated assumption that the objective and subjective realms are disjoint - that is, the two realms have an empty "chasm" in-between. Not so. Just as someone employs binoculars to see a far place, the subjective realm is how someone observes (and interprets!) the objective realm. If event B occurred after event A, then did A cause B? The events A and B are objective, and A may or may not have "really" caused B. But causation is a subjective conclusion applied to these two objective events. A cause and effect relationship is a cooperation between the two realms. In the scientific method, there is a vitally important division between hypotheses and theories and laws (subjective) versus observations and experiments and measurements (objective). One, if not the prime, characteristic of science is a systematic joining of the subjective and objective. Ideally, the resulting synthesis is as objective as possible (Occam's razor). The subjective and objective are unavoidably linked.
- Ethics always involves more than objective truth. This point is the clincher, although it's more tangential to truth per se. Facts do not compel someone to act ethically. Of course, any reasonable decision should be based on facts, but ethics is more about the question "now what?" than "what's going on?". For instance, two people may be in the middle of a miserable situation. One seeks to alleviate it; the other seeks to exploit it for personal advantage. Goals, values, and such are of the subjective realm. When people agree about a common (subjective) ideal, then they can use objective truth to argue for a specific course of action. And sometimes the facts are not in question, yet the ethical debate remains far from over.