The major debate in ethics is whether there are objective moral facts. There are a variety of defenses and objections to either position. Those who say there are objective moral facts are called "realists" while those who deny realism are called anti-realists or nihilists (there are actually more positions such as constructivists and non-cognitivists but let's not worry about that).
A popular strategy realists use is to say that moral reasoning is analogous to either scientific reasoning or mathematical reasoning. In super condensed form, the former strategy plays on the idea that scientific reasoning is a recursive spiraling toward the truth. There's a continuous interplay between hypothesis/theory and observation, the one impacting the other. Hypotheses and theories are tested, confirmed or rejected based on the best available observations. Similarly, hypothesis and theories impact how we interpret our observations.
Moral reasoning is no different. We begin "in the middle" with both a moral theory and observations. Particular observations (judgments) influence our moral theories and theories influence how we interpret our observations. In both domains, there's a back and forth between theory and observation and the trajectory or both enterprises aims at truth.
A similar but slightly different argument applies to the analogy between mathematical and moral reasoning. We just as we can't directly observe mathematical facts, we can't directly observe moral facts. We reason our way to them. Also, both moral and mathematical facts don't have a physical existence yet we are sensitive to them: they inform our actions and our view of the world.
Ok, so those are very simplified versions of the arguments. In "Ethics and Observation," Gilbert Harmon challenges both analogies, although he focuses mostly on the first. Harmon's conclusion (at least not in this article) isn't that there's not such thing as moral truth, rather that the analogy between scientific observation and moral observation doesn't hold.
Let's check out his argoomints...
Part 1: The Basic Issue
Can moral principles be tested and confirmed the same way scientific principles can? On the surface it seems they can. For example, I want to know if the principle "whenever it's possible, you should save 5 lives rather than 1."
How do we test this? Well, we can do a thought experiment and see what our verdict would be. Harmon gives this example:
Suppose you're a doctor in the emergency section. 6 patients are brought in. All six are in danger of dying but one is much worse off than the others. You can just barely save that person if you devote all of your resources to him and let the others die. Or, you can save the other 5 if you are willing to ignore the most seriously injured person.What do? It seems like this case confirms the moral principle in question. However, this being philosophy, there will be counter-examples a-plenty.
You have 5 patients in the hospital who are dying, each in need of separate organ. ONe needs a kidney, another a lung, a third a heart, and so on. You can save all five if you take a single healthy person and remove his heart, lungs, kidneys, etc... to distribute to these five patients. Just such a healthy person walks into the hospital for routine tests. His test results confirm he'd be a match as an organ donor for all 5 dying patients. If you do nothing he'll survive and 5 will die. If you apply our principle of action, that you ought to always save 5 instead of one whenever you can, then, well, you'll save 5 and only lose one life...What do? It seems like we've tested the moral principle and the test disconfirms it. The moral principle is false (or needs to be modified).
So, is this kind of testing the same as is done in the scientific realm? It doesn't look like it. Scienticians test their hypotheses and theories against the real world not just in their "imagination". It doesn't seem like we can perceive the rightness or wrongness of an act the way you might perceive the color, shape, and mass of an object.
How do scienticians know bluebirds are blue? Because they can look out into the world and see the blueness of the bird in question. But how do we know if an act is wrong? It doesn't seem like you can point to the wrongness or rightness the way you can point to an object's physical properties. And so it seems as though there's a way in which scientific and moral observation are different.
How do we make moral judgments anyway? Harmon gives the following case. You're walking down the street and you happen upon two teenagers (damn teenagers!) pouring gasoline on a cat then ignite it. It doesn't seem like you perform any reasoning process. It's not like you go. Hmmm, let me see, there's a moral principle that
P1. causing unnecessary suffering of innocent creatures is wrong, andWhat actually happens is you move directly to the moral judgment. You just see it's wrong. The process is a direct observation that the act is wrong. No reasoning required.
P2. these youths are engaged in an instance of causing unnecessary suffering to an innocent creature,
C. therefore, what they are doing is wrong.
Here's the issue: Are you perceiving something objective or is your reaction simply a product of your particular psychology? That is, if you'd been around when people tortured cats for fun, you might not have made the same judgment from your observation. Likely, your judgment is a reflection of facts about you, not about the act. More on this in a bit...
Part 2: Theory-Laden Observation
Let's get clear on what is meant by observation. In philosophy of science, it's widely recognized that there are no "raw" observations. All observations are "theory-laden." This means that, implicitly or not, we interpret all of our experiences though the lens of a theory of the world. The most basic one is that there are physical things that cause my experiences. This can be a bit difficult to wrap your head around for people who don't live in the wacky world of philosophy but check it out: you don't perceive objects directly...
You have mental representations in "the theatre of your mind" which you interpret as being representative of external physical objects which are the ultimate cause of your perceptual experience. You could be in the matrix with the exact same experiences being piped into your consciousness and nothing would be different. The worlds would be indistinguishable. The leap from the experience as though there are physical objects in my visual field to there are physical objects in my visual field is an unconscious one. But it is nevertheless a theory. You interpret your experiences of the world with the theory that it is physical objects that are causing what you see in your head.
Anyhow, the point is that even at the most fundament level we interpret observations through the lens of a theory. This happens in everyday life and it also happens in science. When a scientician sees a vapor trail in a cloud chamber, he thinks "there's a proton". He has a theory about the fundamental units of matter and the ways they interact with other matter, and that colors his interpretation of the observation. The observation itself doesn't tell him there's a proton. He adds that as a way of interpreting the raw observation. I.e., that he perceive a "proton" is the product of his theory.
Another example comes from biology. Famously (although he has since rejected it), Dawkins interpreted all evolution as being grounded in the selfishness of genes. In short, all selection call be explained by appealing to genes. If you want to know why one trait is more prevalent than another it must be because the genotype responsible for that trait confers greater fitness. His theory of selection (i.e., that genes are the fundamental unit of selection) colors how he interprets evolution.
On the other hand, a competing theory says that, at least for social animals, you have to also take into account group selection; i.e., the unit of select can also be the group. The reason is that altruistic behavior is inexplicable at the genetic level. How can you explain why a genotype that codes for disadvantageous behaviors/traits could outcompete selfish behaviors/traits? The gene-view can't explain it. Disadvantageous traits by definition are disadvantageous and so should be outcompeted by selfish traits. And so this theory views the same evolutionary observations from the level of group selection.
In short, your theory about the unit of section for evolution will color how you interpret the raw data. Same data/raw observations, different interpretation. Your observations are theory-laden.
Similarly, in the moral domain, we interpret our raw observations though the lens of a theory about the world. You have a theory of the moral domain that causes you to judge the teenagers torturing the cat as wrong. If you had a different (moral) theory of the world that excluded animals from the moral domain, you'd interpret your observation differently. Your moral observations are theory-laden.
In that observations are theory-laden, moral and non-moral judgments are alike. The theory we hold of the world colors how we interpret the raw observations in both domains. If there's a difference between moral and scientific observation, it must be something else...
Part 3: Observational Evidence
Here's the difference: In science you need to make assumptions about certain physical facts in order to asplain an observation. In ethics you don't have to assume there are moral facts; alz you need to do it know something about a person's psychology; you can explain someone's observation that an act is wrong based merely on facts about the observer.
The way I like to think about this is to imagine (some of you won't have to imagine cuz you already have this theory) that there are no objective moral facts. There are only moral opinions that arise out of upbringing and psychological disposition. Would the world appear to be any different? People would still opine on what is right or wrong. People would agree on some things, disagree on others. Everything would seem exactly the same...and we could explain people's observations too. We could say, this person believes x is right because his mommy told him so or this person thinks y is wrong because she has an aversion to it. There'd be no unexplainable observations even if there were no moral facts.
Things are different in the case of science. To make a scientific observation you have to assume that there are objective facts about the world. I.e., there is matter and energy, and so on. When I observe that there's a cloud of vapor in a cloud chamber, the only way I can explain it is if I assume there are objective facts about the world: I.e., there's matter. I have theory that there are protons; I observe "stuff" happening that conforms with my theory. Thus, my theory is provisionally confirmed.. And unlike moral observations, you can't explain my observations by merely appealing to facts about my particular psychology and upbringing. You can't explain my observation without also assuming there are protons...there has to something there for me to observe!
To summarize thus far: you can asplain the moral observation ("that's wrong!") by merely appealing to psychological facts about the observer. Moral facts don't need to be "real" to explain why someone might make the judgment. On the other hand, you can't asplain why someone would observe what they take to be a proton unless there actually was something real that existed. They could be wrong about it being a proton, maybe it was a neutron but they had to observe something to explain why they report observing a proton. There must be some fact about the world in order to explain their observation. Merely appealing to psychological facts about the observer won't explain why they had the scientific observation/judgement they did.
Observations as Evidence for Theories
If I have a scientific theory that predicts a particle with such and such properties, observable under such a such conditions, observation of such a phenomena counts as confirming evidence for my theory. But is this the case with moral observations and theories?
Does my observation/judgment that burning the cat is wrong lend credence to my theory that says that it's objectively wrong to burn cats? Let's return to imagining there are no objective moral facts. My judgment doesn't confirm my theory. I'm just extending my theory (i.e., beliefs) to the observation. This will happen regardless of whether there is an objective moral fact about the matter or not.
Again we can contrast this with the scientific observation. If my theory predicts protons but there are no protons (or nothing with the properties my theory predicts), this will impact my theory. Whether there are or are not objective facts about the world matters for scientific observation and their effect on theory.
Let's slow down and make a distinction here between types of observation. There's a sense in which my observation that "it's wrong to torture cats" confirms my moral theory. For example, I have a theory with the principle that it's wrong to cause unnecessary harm and suffering to innocent sentient beings. I see the teenagers lighting the cat and I immediately observe that the act is wrong. It is an instance of causing unnecessary harm and suffering and I observed it to be wrong. That confirms my moral principle. I said that such acts are wrong, I witnessed an instance of such an act, and I also observed that it was wrong. Moral principle is confirmed!
However, there's another sense of observation in which my observation doesn't confirm my theory because it doesn't explain why I think the act is wrong. My observation conforms with my moral theory, that such acts are wrong, but it isn't evidence in favor of my principle. We can imagine another person a few centuries ago who thought it's great entertainment to light cats on fire. They can witness the exact same act, judge that it's not wrong and say "ah! that confirms my theory that it's not wrong to cause harm and suffering to animals! My judgment confirms it!"
Not so in the case of science. If a theory predicts an entity with certain properties and those properties are observed, observing the properties explains why someone has the observation they do. And, bonus, the observation is evidence in favor of their theory/hypothesis. If no entity were observed with the predicted properties, the observation couldn't be made. In short, the scientific (physicalist) theory explains why you observe the entity and properties that you do because the theory is about how the world is. Even if you believed the theory to be false, you'd still have the same observation:
Think Galileo. When the Church officials looked through his telescope, they didn't believe his theory yet what they observed confirmed Galileo's theory, rather than theirs. Their theoretical beliefs couldn't prevent them from seeing the evidence that disconfirmed their own theory and confirmed Galileo's. (Although, in the end they decided to reject the evidence rather than their theory...)
Possible Objection: Scienticians can (and have for all of scientific history) observe the exact same phenomena yet disagree on the theoretical interpretation of the observation. For example, both gene-based and group selection-based evolutionists observe the exact same phenomena. They don't disagree about what's happening. Evolution through differential reproduction and natural section is happening. They disagree about what theory best explains differential reproduction and natural selection. And so, it looks like, in some respects, scientific observation is similar to moral observation.
Two people can observe the exact same thing and disagree as to what theory the observation supports. Just as two people can observe kids torturing a cat and disagree as to whether the case supports their particular moral theories on the treatment of animals, two scientists can both observe the exact same instances of differential reproduction and natural selection and disagree over the unit of selection to explain the observation. That is, they can disagree at the level of theory about how to interpret the observation.