The is/ought gap illustrates the difficulty in understanding what it means to say that we ought to do something, and how we can know what we ought to do. What is the is/ought gap and what’s it all about? I will describe the is/ought gap, discuss its implications in meta-ethics, and discuss various solutions to the is/ought gap.
What is the is/ought gap?
The is/ought gap is a problem in moral philosophy where what is the case and what ought to be the case seem quite different, and it presents itself as the following question to David Hume: How do we know what morally ought to be the case from what is the case?
Hume posed the question in A Treatise of Human Nature Book III Part I Section I:
In every system of morality, which I have hitherto met with, I have always remark’d that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs, when of a sudden I am surpriz’d to find, that instead of the usual copulations of propositions, is and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, ‘tis necessary that it shou’d be observ’d and explain’d; and at the same time that a reason shou’d be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it.
It is here that Hume points out that philosophers argue about various nonmoral facts, then somehow conclude what ought to be the case (or what people ought to do) based on those facts (about what is the case). For example, we might find out that arsenic is poisonous and conclude that we ought not consume it. But we need to know how nonmoral facts can lead to moral conclusions. These two things seem unrelated.
The is/ought gap doesn’t seem like a problem for nonmoral oughts—what we ought to do to accomplish our goals, fulfill our desires, or maintain our commitments. For example, we could say, “If you want to be healthy, you ought not consume arsenic.” However, it might be morally wrong to consume arsenic. If it is, we have some more explaining to do.
Some of the things we ought to do are obligations, but not everything we ought to do is an obligation. For example, we can be obligated to meet a friend for lunch after making a promise to. The difference between what we are obligated to do and other things we ought to do isn’t entirely clear, but it’s generally considered to be morally wrong when we fail to fulfill a moral obligation. When dealing with morality, our moral obligations tend to be what we consider to be of greater importance than other things we ought to do. For example, it might be that I morally ought to give half my money to charity, but it wouldn’t be wrong if I don’t. On the other hand it’s morally wrong to steal from a charity and I’m obligated not to do that.
The is/ought gap is similar to the fact/value gap. Some people think that nonevaluative facts and values are totally different things. They think we know nonevaluative facts, but it’s not clear how we know what’s valuable—what moral values we ought to promote. For example, some people think pleasure is good and pain is bad. We ought to give ourselves and others pleasure, but we ought not to give ourselves or others pain. It’s not obvious how we know what has moral value, but values will be discussed in greater detail below.
The meta-ethical implications
First, the is/ought gap requires us to better understand the concept of a “moral ought.” Second, it might be evidence for moral anti-realism.
What is a “moral ought?”
The is/ought gap doesn’t seem like a problem unless we are dealing with what “morally ought” to be the case. For example, if you tell a person that it’s morally wrong to put arsenic in someone else’s food. There’s no consensus about what distinguishes a moral ought from a nonmoral ought, but there are many common assumptions that we seem to have about them. For example:
- We ought not do something if it’s morally wrong.
- It’s morally wrong to kill people indiscriminately.
- All things equal, it’s morally right to save people’s lives.
- If someone does something very morally wrong, like killing people indiscriminately, then that person should be blamed for the action and should be punished for it.
- What we morally ought to do overrides our nonmoral obligations.
- I morally ought to save the life of a small child when doing so is at little cost to myself, even if I will then fail to meet my friend for lunch on time after promising to do so.
- What I morally ought not do isn’t changed by wanting to do it. For example, I morally ought not to kill people indiscriminately, even if I want to do it.
- We can be wrong about what we ought to do (or ought not do). A person can think that killing people indiscriminately isn’t wrong, but that belief would be false.
- People often argue about what we morally ought to do, and we can disagree about what we should belief regarding morality.
- Some moral beliefs are more justified than others. It seems irrational to believe that it’s never wrong to indiscriminately kill people, and such a belief seems unjustified. In contrast, the belief that it is wrong to kill people indiscriminately seems justified.
- Some actions are good, but they aren’t obligations. For example, it’s good to save a child from a burning building, but it’s often too dangerous to be morally required of us.
- We should be moral, even if we aren’t motivated by external rewards or punishments. For example, dying to protect one’s friends from a grizzly bear is sometimes morally right, even though it leads to the ultimate personal sacrifice.
How is the is/ought gap evidence of moral anti-realism?
Moral anti-realists think that there are no irreducible moral facts—all moral truths can be reduced to our beliefs, desires, commitments, and so on. Anti-realists don’t think that anything is right or wrong apart from something like a social contract—it’s practical to commit ourselves to behaving ethically insofar as we will benefit when everyone else makes the same commitment as well. Three reasons that the is/ought gap is often taken to be evidence for anti-realism is because (a) the anti-realist sees no reason to think that what morally ought to be the case is a “moral fact” beyond our beliefs, desires, and commitments; (b) the anti-realist sees no reason to think that we could ever know such moral facts exist; and (c) the anti-realist solutions to the is/ought gap could be superior to the realist solutions.
Is what morally ought to be the case a moral fact? Facts are states of affairs—actual things that exist and relations between things that exist. That a cat is on the mat is a fact. It’s unclear how what morally ought to be the case can be a fact. What morally ought to be is often quite different from the actual state of affairs in the world. A thief steals, a murderer kills, and so on. People aren’t actually doing what they ought to do. How can a state of affairs that ought to exist be said to be a fact when what ought to be the case is often quite different from what actually exists or happens in the world? Anti-realists see no good answers for these questions, but they think anti-realism can solve the problem by avoiding it. If there are no moral facts, then we no longer need to answer these questions.
How can we know what morally ought to be the case? Hume was an empiricist, so he thought we could only know about reality through observation. What we observe isn’t necessarily what ought to be. The actual state of affairs in the world can be quite different that what people morally ought to do. We do know what is the case because we can observe it. Looking at what is the case—the actually obtaining nonmoral facts—doesn’t seem to tell us what ought to be the case. So, it’s not obvious how we can know what morally ought to be the case assuming that it’s a moral fact. Anti-realists think that we can avoid this problem entirely by becoming anti-realists and admitting there are no moral facts.
Solutions to the is/ought gap
There are many potential solutions to the is/ought gap, and they aren’t always mutually exclusive. Additionally, there are two main approaches to the problem: (1) Understanding the concept of what morally ought to be the case can help us know how to get what ought to be the case from what is the case, and (2) we can provide intuitive answers and compare/contrast each solution to see which is best. Most philosophers try to use a combination of these two approaches.
A Platonic Solution
Plato was a moral realist who thought that there are ideal forms (abstract objects) that exist in the world as ideal “perfect” things. There’s perfect goodness, perfect virtue, perfect courage, and so on. In some sense what ought to be the case really does exist—as the forms. We can somehow know these forms through contemplation or intuition. Perhaps we experienced the forms before we were born and can remember them throughout our lives. For Plato certain forms are “moral facts” that exist in a way similar to any other state of affairs. We ought to acquire characteristics of the forms, such as goodness, virtue, justice, wisdom, and moderation. Once we have those characteristics (perfections or virtues), we will do what we morally ought to. No one acquires virtues completely, and people who do so well are better people who don’t.
Simply put, the Platonic solution is that what ought to be the case is based primarily on actually existing abstract objects, and we are “what ought to be” insofar as we approximate these objects. What we ought to do is based on what we will do naturally once we are perfect.
There are at least two strong objections to this Platonic view. First, it seems overly-ambitious and far-fetched. We shouldn’t accept new forms of reality to exist when no such assumptions are required. Second, it’s unclear how contemplation or intuition can give us knowledge of the forms.
A Theistic Solution
Theists can have a solution similar to the Platonic solution, but they can replace the forms with God. God is perfect goodness, and we ought to be as much like God as possible. Insofar as we approximate God, we will do what we ought to naturally, and insofar as we fail to approximate God, we won’t.
Aristotle developed teleology—the idea that there are goals infused in nature. He thought that each being has a natural telos (goal), which is its perfection (flourishing). A seed’s telos can be a fully developed tree, and the telos of a small child is to develop into a virtuous and political adult with a developed rational capacity. For Aristotle what ought to be the case is based on the natural tendency and potentiality to flourish. As human beings we naturally desire our telos and fulfillment of our telos rewards us with happiness.
For Aristotle what “ought to be the case” is based on a potentiality rather than what actually exists, but he thinks this potentiality is part of actually existing things. We can figure out our potentiality through our rational desires and through observation.
There are at least two important objections to Aristotle’s solution. First, it’s unclear that natural objects really do have a natural telos. Second, it’s unclear that rational desires and observation can help us discover the telos of beings, even if they do have a telos.
Torbjörn Tännsjö’s Solution
Tännsjö is a moral realist who argues that there are intrinsic values—some things are good or bad just for existing. In particular, he believes that pleasure is intrinsically good and pain is intrinsically bad. He thinks we ought to maximize pleasure and minimize pain, and everyone counts. He basically embraces utilitarianism in this regard. He thinks it’s morally right to maximize goodness, and it’s morally wrong not to. (My understanding is that Sam Harris’s Moral Landscape endorses a view much like Tännsjö’s.)
How do we know about intrinsic values? Tännsjö thinks we can observe that they exist. Pain seems to be intrinsically good when we experience it, and pain seems to be intrinsically bad when we experience it.
Why exactly is what morally ought to be the case based on intrinsic value? Tännsjö argues that this is simply what he thinks we should mean by what we morally ought to do based on something like a social contract, and this view is quite intuitive. It certainly seems like we ought not to cause ourselves excessive pain based on how it feels to us, and it also seems intuitive to think it’s wrong to cause other people excessive pain as well.
He is a moral realist because he believes in irreducible moral facts (i.e. intrinsic values), but what “morally ought to be the case” is not itself an irreducible moral fact. His view is a minimalistic moral realist view that admits that moral anti-realists can be right about many things, but he thinks the anti-realist wrongly denies that intrinsic values exist.
There are at least five objections to Tännsjö’s solution. First, many people are unconvinced that intrinsic values exist. Second, many people deny that we can experience that pleasure is intrinsically good or pain is intrinsically bad. Third, many people think there’s more intrinsic values than merely pleasure and pain. Fourth, many people think that we need more than a social contract and intrinsic values to know what “morally ought to be the case.” Perhaps murder is wrong, even if there is no social contract, and when we disagree about morality, we aren’t just disagreeing about the actual social contract that exists. Fifth, many people are unconvinced that right and wrong are determined by utilitarianism, and many counterexamples have been given against it.
David Hume’s Solution
Hume rejects that there are irreducible moral facts. Instead, what we morally ought to do is based on our sentiments. In particular, our sympathy for others. When we say that murder is wrong, we are stating our repulsion towards murder based on our sympathy for the victim.
For Hume, there’s no major difference between what morally ought to be the case or what nonmorally ought to be the case based on our goals. Both sorts of “ought” are based on our sentiments. The difference is mainly just that what morally ought to be is based on sympathy in particular. Many philosophers agree with Hume, and similar views about morality has continued though the “moral sentimentalist” and “care ethics” traditions.
The main problem with Hume’s solution is that it seems incompatible with many common assumptions regarding morality. First, it seems to contradict the assumption that desires can’t override what we morally ought to do. Second, it seems to contradict the assumption that our personal goals can’t override what we morally ought to do. Third, it seems to contradict the assumption that we can be wrong about what morally ought to be the case. Fourth, it seems to contradict our assumption that some moral goals are more reasonable than others.
A Hobbsian Solution
Thomas Hobbes also denies that there are moral facts, and he thinks we can know what morally ought to be the case based purely on practical reason through a social contract. We all have shared interests and we can agree to behave a certain way for our mutual benefit. For example, we can all agree not to kill each other indiscriminately because we all have an interest in staying alive. We can then also pass laws and agree that people who break the social contract will be punished to help “keep people in line” and be assured that people will stay faithful to the contract.
Again, Hobbes’s solution seems incompatible with many common assumptions. First, it’s unclear how Hobbes can accept that what we morally ought to do can override what we nonmorally ought to do. Second, it’s unclear how Hobbes can accept that people who do good that’s not required of them by the social contract are still doing what’s morally praiseworthy.
Lawrence Becker’s Solution
Becker argues that we can get a nonmoral ought by finding out what we ought to do based on our goals nothing-else-considered, but we ought to do what we morally ought to do based on our goals (and whatever else) all-things-considered. In other words, you ought to fulfill your desires (nonmorally), but you morally ought to fulfill your desires as long as there’s no overriding reason against it. If you want to eat chocolate and there’s no conflicting reason not to, then you should do it. He expects that people will have an overriding reason not to commit murder or become thieves.
There are at least three objections to Becker’s solution. First, it’s very abstract. It’s not yet clear what reasons we can have against behaving in certain ways. For example, what exactly is the reason against murdering people when we want to murder people? Second, it seems to lack importance. Why say you morally ought to eat chocolate? That seems too petty to be ranked as what we morally ought to do. Third, if it’s true, then it’s unclear why it’s true. Why is it that we morally ought to do whatever is necessary to achieve our goals as long as we don’t have overriding reasons not to? And what makes any reason overriding?
The is/ought gap doesn’t seem like a serious problem for moral realism because almost no moral realist philosopher has ever thought that “what you morally ought to do” actually exists as an irreducible moral fact. However, what you morally ought to be could be part of our nature or it could exist in the forms. Additionally, moral realists like Tännsjö don’t think that what “morally ought to be the case” needs to be irreducible moral facts at all. Instead, we can rely on intrinsic values as a basis for morality and accept anti-realist beliefs whenever they are sufficiently plausible. The problem with anti-realism (if anything) is that it’s incomplete rather than that it’s entirely false—and we are likely to have assumptions that seem incompatible with anti-realism.
Nonetheless, the anti-realist solutions (of Hume and Hobbes) could be more plausible than the realist ones, and that in itself could be a challenge to moral realism.