Act only according to that maxim whereby you can, at the same time, will that it should become a universal law.
If everyone were to stop having kids so they could donate more money to charity, the following would happen:
there would be a lot less starvation and disease in the next couple of decades
humanity would vanish in about seven decades
So you can’t want the maxim “stop having kids so you can donate more to charity” to become a universal law; thus (according to Kant) you shouldn’t follow the maxim yourself.
That’s like saying that being a computer programmer is immoral, because if everyone would become a computer programmer, no one would cultivate food, and within a month the humanity would vanish.
It’s possible to make a more complex algorithm saying that those who have a comparative advantage in computer programming should become computer programmers and those who have a comparative advantage in cultivating food should cultivate food. This way humanity can survive.
Analogically we should be thinking about consequences of a world where people with a comparative advantage in donating don’t have children and instead donate the money to efficient charities, and some other people have children and ensure that humanity survives. -- There are some things that could go wrong in that scenario, but it’s not that trivially wrong.
(Also, it is important to note that most people don’t behave according to Kant’s rules, so even a strategy that would maximize global utility if everyone used it, is not necessarily the global utility maximizing choice for an individual in real life.)
EDIT: I am not deeply familiar with Kant’s philosophy. It just seems to me that it makes sense to seek an algorithm that maximizes global utility when used by everyone, but it would be stupid to require that the algorithm produce the same output for everyone. If two people have different comparative advantages, they can both use an algorithm “do what is your comparative advantage and trade with the other person”, and yet their behavior will not be identical. Children are valuable, in my opinion; the topic of this discussion is that maybe some people can create a lot more value by doing something else.
From Daniel’s post, it seems like the categorical imperative defines whether some behavior could be considered morally required, not whether a particular behavior is immoral. Being a computer programmer couldn’t be morally required of everyone, but that doesn’t mean that it is immoral for some people to be computer programmers.
It seems to me that the best way to capture Kant’s intent and avoid these sort of computer programmer problems is to interpret the first categorical imperative as saying something like “always choose in such a way that your choice can universally rationally be regarded as valuable.” This seems to make it possible to endorse some people being computer programmers while others farm, without so far as I can tell endorsing having some people tell the truth while others lie. It also, incidentally, helps slightly narrow the gap between the first and second categorical imperatives, which is an advantage as a matter of Kant exegesis since Kant insists the first and second (and third) CI are in fact the same. I’m not actually certain what this interpretation would say about the choice to be childless, but then one of the reasons I’m not a Kantian myself is that I think it’s much harder than Kant pretended, indeed sometimes impossible, to figure out what the CI actually recommends. Only a few cases work out as neatly as Kant’s preferred example of lying (and even that case is probably more difficult than Kant admits).
On the other hand, Kant’s imperative does not obviously oppose the maxim “stop having kids so you can donate more to charity for as long as the marginal value of another child is lower than the marginal value of your differential charitable contributions.” (Nor does it obviously oppose a large number of other competing maxims.)
Kant’s Categorical Imperative is directly applicable to this problem.
Can you expand on that a bit?
Sure. The principle says
If everyone were to stop having kids so they could donate more money to charity, the following would happen:
there would be a lot less starvation and disease in the next couple of decades
humanity would vanish in about seven decades
So you can’t want the maxim “stop having kids so you can donate more to charity” to become a universal law; thus (according to Kant) you shouldn’t follow the maxim yourself.
That’s like saying that being a computer programmer is immoral, because if everyone would become a computer programmer, no one would cultivate food, and within a month the humanity would vanish.
It’s possible to make a more complex algorithm saying that those who have a comparative advantage in computer programming should become computer programmers and those who have a comparative advantage in cultivating food should cultivate food. This way humanity can survive.
Analogically we should be thinking about consequences of a world where people with a comparative advantage in donating don’t have children and instead donate the money to efficient charities, and some other people have children and ensure that humanity survives. -- There are some things that could go wrong in that scenario, but it’s not that trivially wrong.
(Also, it is important to note that most people don’t behave according to Kant’s rules, so even a strategy that would maximize global utility if everyone used it, is not necessarily the global utility maximizing choice for an individual in real life.)
EDIT: I am not deeply familiar with Kant’s philosophy. It just seems to me that it makes sense to seek an algorithm that maximizes global utility when used by everyone, but it would be stupid to require that the algorithm produce the same output for everyone. If two people have different comparative advantages, they can both use an algorithm “do what is your comparative advantage and trade with the other person”, and yet their behavior will not be identical. Children are valuable, in my opinion; the topic of this discussion is that maybe some people can create a lot more value by doing something else.
From Daniel’s post, it seems like the categorical imperative defines whether some behavior could be considered morally required, not whether a particular behavior is immoral. Being a computer programmer couldn’t be morally required of everyone, but that doesn’t mean that it is immoral for some people to be computer programmers.
It seems to me that the best way to capture Kant’s intent and avoid these sort of computer programmer problems is to interpret the first categorical imperative as saying something like “always choose in such a way that your choice can universally rationally be regarded as valuable.” This seems to make it possible to endorse some people being computer programmers while others farm, without so far as I can tell endorsing having some people tell the truth while others lie. It also, incidentally, helps slightly narrow the gap between the first and second categorical imperatives, which is an advantage as a matter of Kant exegesis since Kant insists the first and second (and third) CI are in fact the same. I’m not actually certain what this interpretation would say about the choice to be childless, but then one of the reasons I’m not a Kantian myself is that I think it’s much harder than Kant pretended, indeed sometimes impossible, to figure out what the CI actually recommends. Only a few cases work out as neatly as Kant’s preferred example of lying (and even that case is probably more difficult than Kant admits).
On the other hand, Kant’s imperative does not obviously oppose the maxim “stop having kids so you can donate more to charity for as long as the marginal value of another child is lower than the marginal value of your differential charitable contributions.” (Nor does it obviously oppose a large number of other competing maxims.)