I was watching the Fox News Channel late-night program Red Eye the other night, when for some reason the topic of the is-ought dichotomy came up.
As you probably know, the is-ought dichotomy was first identified by the 18th-century philosopher David Hume, who observed that it's impossible to derive a value judgment -- an ought -- from facts alone. The problem was largely ignored in his time, but has proved vexing to more recent philosophers. Many attempts have been made to bridge the gulf between is and ought. All have failed. There does not seem to be any way of resolving the dichotomy.
On Red Eye, one of the panelists suggested that the dichotomy posed no real problem by giving this example: "It is raining. Therefore I ought to take my umbrella." He then shrugged, as if to say: See? Solved it for you.
Red Eye is a pretty unserious show, which consists mostly of playful banter broken up by YouTube clips of funny animals, so I don't know if the brief discussion was meant to be taken seriously or not. But if this was a legitimate suggestion, it was mistaken. The example given does not resolve the dichotomy. The reason is that the line of reasoning presented includes a hidden step, which is implied but not stated. Let's restate the argument with the hidden step made explicit.
1. It is raining.
2. I prefer not to get wet.
3. Therefore I ought to take my umbrella.
Here we can clearly see that the ought statement is predicated on step two, a personal preference.
Now, no one has ever denied that ought statements can be derived from personal preferences. The point of the is-ought dichotomy is that ought statements cannot be derived from neutral facts. And that is indeed true. It is impossible to derive step three from step one without the intervention of step two.
In fact, virtually all ought statements derive from statements of preference, even if these statements are implicit. You can easily test this yourself by making just about any ought statement you can think of, and then identifying the preference that underlies it. The only arguable exceptions are ought statements based on instincts, such as the will to live. An instinct may be seen as only a deeply ingrained preference, or it may be seen as brute biological fact, depending on one's point of view.
Does this mean that all moral values are based on personal subjective preferences and, possibly, a few biological drives? That's the position taken by most contemporary secular humanists.
The alternative is that objective moral values unconnected to biology do exist, but that they are not derived not from empirical observations. Instead, they are derived from a deep, intuitive insight into the nature and purpose of the universe and/or its Creator - a precious gift, a pearl beyond price, handed down to the rest of us by a small number of gifted spiritual teachers. Of course, this takes us into the realm of mysticism and revelation, a step which is understandably offputting to many moderns, and which gives rise to problems of its own.
Still, if we are going to live in a world of objective moral values instead of mere subjective preferences and blind animalistic instincts, then the is-ought dichotomy tells us we must go beyond the limits of logic. Because logic, it seems, can take us only so far.