To be clear I see the deontologist optimization problem as being a pure “feasibility” problem: one has hard constraints and zero gradient (or approximately zero gradient) on the moral objective function given all decisions that one can make.
Of the many, many critiques of utilitarianism some argue that its not sensible to actually talk about a “gradient” or marginal improvement in moral objective functions. Some argue this on the basis of computational constraints: there’s no way that you could ever reasonably compute a moral objective function (because the consquences of any activity are much to complicated) to other critiques that argue the utilitarian notion of “utility” is ill-defined and incoherent (hence the moral objective function has no meaning). These sorts of arguments undermine argue against the possibility of soft-constraints and moral objective functions with gradients.
The deontological optimization problem, on the other hand, is not susceptible to such critiques because the objective function is constant, and the satisfaction of constraints is a binary event.
I would also argue that the most hard-core utilitarian practically acts pretty similarly to a deontologist. The reason is that we only consider a tiny subspace of all possible decisions, and our estimate of the moral gradient will be highly inaccurate over most possible decision axis (I buy the computational-constraint critique), and its not clear that we have enough information about human experience in order to compute those gradients. So, practically speaking: we only consider a small number of different way to live our lives (hence we optimize over a limited range of axes) and the directions we optimize over is not-random for the most part. Think about how most activists and most individuals who perform any sort of advocacy focus on a single issue.
Also consider the fact that most people don’t murder or perform certain forms of horrendous crimes. These single issue thinking, law-abiding types may not think of themselves as deontologist but a deontologist would behave very similarly to them since neither attempts to estimate moral gradients over decisions and treats many moral rules as binary events.
The utilitarian and the deontologist are distinguished in practice in that the utilitarian computes a noisy estimate of the moral gradient along a few axes of their potential decision-space: while everywhere else we think of hard constraints and no gradients on the moral objective. The pure utilitarian is at best a theoretical concept that has no potential basis in reality.
Some argue this on the basis of computational constraints: there’s no way that you could ever reasonably compute a moral objective function (because the consquences of any activity are much to complicated)
This attacks a straw-man utilitarianism, in which you need to compute precise results and get the one correct answer. Functions can be approximated; this objection isn’t even a problem.
to other critiques that argue the utilitarian notion of “utility” is ill-defined and incoherent (hence the moral objective function has no meaning).
A utility function is more well-defined than any other approach to ethics. How do a deontologist’s rules fare any better? A utility function /provides/ meaning. A set of rules is just an incomplete utility function, where someone has picked out a set of values, but hasn’t bothered to prioritize them.
This attacks a straw-man utilitarianism, in which you need to compute precise results and get the one correct answer. Functions can be approximated; this objection isn’t even a problem.
Not every function can be approximated efficiently, though. I see the scope of morality as addressing human activity where human activity is a function space itself. In this case the “moral gradient” that the consequentialist is computing is based on a functional defined over a function space. There are plenty of function spaces and functionals which are very hard to efficiently approximate (the Bayes predictors for speech recognition and machine vision fall into this category) and often naive approaches will fail miserably.
I think the critique of utility functions is not that they don’t provide meaning, but that they don’t necessarily capture the meaning which we would like. The incoherence argument is that there is no utility function which can represent the thing we want to represent. I don’t buy this argument mostly because I’ve never seen a clear presentation of what it is that we would preferably represent, but many people do (and a lot of these people study decision-making and behavior whereas I study speech signals). I think it is fair to point out that there is only a very limited biological theory of “utility” and generally we estimate “utility” phenomenologically by studying what decisions people make (we build a model of utility and try to refine it so that it fits the data). There is a potential that no utility model is actually going to be a good predictor (i.e. that there is some systematic bias). So, I put a lot of weight on the opinions of decision experts in this regard: some think utility is coherent and some don’t.
The deontologist’s rules seem to do pretty well as many of them are currently sitting in law books right now. They form the basis for much of the morality that parents teach their children. Most utilitarians follow most of them all the time, anyway.
My personal view is to do what I think most people do: accept many hard constraints on one’s behavior and attempt to optimize over estimates of projections of a moral gradient along a few dimensions of decision-space. I.e. I try to think about how my research may be able to benefit people, I also try to help out my family and friends, I try to support things good for animals and the environment. These are areas where I feel more certain that I have some sense where some sort of moral objective function points.
To be clear I see the deontologist optimization problem as being a pure “feasibility” problem: one has hard constraints and zero gradient (or approximately zero gradient) on the moral objective function given all decisions that one can make.
Of the many, many critiques of utilitarianism some argue that its not sensible to actually talk about a “gradient” or marginal improvement in moral objective functions. Some argue this on the basis of computational constraints: there’s no way that you could ever reasonably compute a moral objective function (because the consquences of any activity are much to complicated) to other critiques that argue the utilitarian notion of “utility” is ill-defined and incoherent (hence the moral objective function has no meaning). These sorts of arguments undermine argue against the possibility of soft-constraints and moral objective functions with gradients.
The deontological optimization problem, on the other hand, is not susceptible to such critiques because the objective function is constant, and the satisfaction of constraints is a binary event.
I would also argue that the most hard-core utilitarian practically acts pretty similarly to a deontologist. The reason is that we only consider a tiny subspace of all possible decisions, and our estimate of the moral gradient will be highly inaccurate over most possible decision axis (I buy the computational-constraint critique), and its not clear that we have enough information about human experience in order to compute those gradients. So, practically speaking: we only consider a small number of different way to live our lives (hence we optimize over a limited range of axes) and the directions we optimize over is not-random for the most part. Think about how most activists and most individuals who perform any sort of advocacy focus on a single issue.
Also consider the fact that most people don’t murder or perform certain forms of horrendous crimes. These single issue thinking, law-abiding types may not think of themselves as deontologist but a deontologist would behave very similarly to them since neither attempts to estimate moral gradients over decisions and treats many moral rules as binary events.
The utilitarian and the deontologist are distinguished in practice in that the utilitarian computes a noisy estimate of the moral gradient along a few axes of their potential decision-space: while everywhere else we think of hard constraints and no gradients on the moral objective. The pure utilitarian is at best a theoretical concept that has no potential basis in reality.
This attacks a straw-man utilitarianism, in which you need to compute precise results and get the one correct answer. Functions can be approximated; this objection isn’t even a problem.
A utility function is more well-defined than any other approach to ethics. How do a deontologist’s rules fare any better? A utility function /provides/ meaning. A set of rules is just an incomplete utility function, where someone has picked out a set of values, but hasn’t bothered to prioritize them.
Not every function can be approximated efficiently, though. I see the scope of morality as addressing human activity where human activity is a function space itself. In this case the “moral gradient” that the consequentialist is computing is based on a functional defined over a function space. There are plenty of function spaces and functionals which are very hard to efficiently approximate (the Bayes predictors for speech recognition and machine vision fall into this category) and often naive approaches will fail miserably.
I think the critique of utility functions is not that they don’t provide meaning, but that they don’t necessarily capture the meaning which we would like. The incoherence argument is that there is no utility function which can represent the thing we want to represent. I don’t buy this argument mostly because I’ve never seen a clear presentation of what it is that we would preferably represent, but many people do (and a lot of these people study decision-making and behavior whereas I study speech signals). I think it is fair to point out that there is only a very limited biological theory of “utility” and generally we estimate “utility” phenomenologically by studying what decisions people make (we build a model of utility and try to refine it so that it fits the data). There is a potential that no utility model is actually going to be a good predictor (i.e. that there is some systematic bias). So, I put a lot of weight on the opinions of decision experts in this regard: some think utility is coherent and some don’t.
The deontologist’s rules seem to do pretty well as many of them are currently sitting in law books right now. They form the basis for much of the morality that parents teach their children. Most utilitarians follow most of them all the time, anyway.
My personal view is to do what I think most people do: accept many hard constraints on one’s behavior and attempt to optimize over estimates of projections of a moral gradient along a few dimensions of decision-space. I.e. I try to think about how my research may be able to benefit people, I also try to help out my family and friends, I try to support things good for animals and the environment. These are areas where I feel more certain that I have some sense where some sort of moral objective function points.
What is the justification for the incoherence argument? Is there a reason, or is it just “I won’t believe in your utility function until I see it”?