Let me politely disagree with this post. Yes, often desires (“wants”) are neither rational nor irrational, but that’s far from always the case. Let’s begin with this:
But the fundamental preferences you have are not about rationality. Inconsistent actions can be irrational if they’re self-defeating, but “inconsistent preferences” only makes sense if you presume you’re a monolithic entity, or believe your “parts” need to all be in full agreement all the time… which I think very badly misunderstands how human brains work.
In the above quote you could simply replace “preferences” with “beliefs”. The form of argument wouldn’t change, except that you now say (absurdly) that beliefs, like preferences, can’t be irrational. I disagree with both.
One example of irrational desires is Akrasia (weakness of will). This phenomenon occurs when you want something (eat unhealthy, procrastinate, etc) but do not want to want it. In this case the former desire is clearly instrumentally irrational. This is a frequent and often serious problem and adequately labeled “irrational”.
Note that this is perfectly compatible with the brain having different parts: E.g.: The (rather stupid) cerebellum wants to procrastinate, the (smart) cortex wants to not procrastinate. When in contradiction, you should listen to your cortex rather than to your cerebellum. Or something like that. (Freud called the stupid part of the motivation system the “id” and the smart part the “super ego”.)
Such irrational desires are not reducible to actions. An action can fail to obtain for many reasons (perhaps it presupposed false beliefs) but that doesn’t mean the underlying desire wasn’t irrational.
Wants are not beliefs. They are things you feel.
Feelings and desires/”wants” are not the same. It’s the difference between hedonic and preference utilitarianism. Desires are actually more similar to beliefs, as both are necessarily about something (the thing which we believe or desire), whereas feelings can often just be had, without them being about anything. E.g. you can simply feel happy without being happy about something specific. (Philosophers call mental states that are about something “intentional states” or “propositional attitudes”.)
Moreover, sets of desires, just like sets of beliefs, can be irrational (“inconsistent”). For example, if you want x to be true and also want not-x to be true. That’s irrational, just like believing x while also believing not-x. A more complex example from utility theory: If P describes your degrees of belief in various propositions, and U describes your degrees of desire that various proposition are true, and P(A and B)=0, then P(A or B)U(A or B)=P(A)U(A)+P(B)U(B). In other words, if you believe two propositions to be mutually exclusive, your expected desire for their disjunction should equal the sum of your expected desires for the individual propositions, a form of weighted average.
Let me politely disagree with this post. Yes, often desires (“wants”) are neither rational nor irrational, but that’s far from always the case. Let’s begin with this:
In the above quote you could simply replace “preferences” with “beliefs”. The form of argument wouldn’t change, except that you now say (absurdly) that beliefs, like preferences, can’t be irrational. I disagree with both.
One example of irrational desires is Akrasia (weakness of will). This phenomenon occurs when you want something (eat unhealthy, procrastinate, etc) but do not want to want it. In this case the former desire is clearly instrumentally irrational. This is a frequent and often serious problem and adequately labeled “irrational”.
Note that this is perfectly compatible with the brain having different parts: E.g.: The (rather stupid) cerebellum wants to procrastinate, the (smart) cortex wants to not procrastinate. When in contradiction, you should listen to your cortex rather than to your cerebellum. Or something like that. (Freud called the stupid part of the motivation system the “id” and the smart part the “super ego”.)
Such irrational desires are not reducible to actions. An action can fail to obtain for many reasons (perhaps it presupposed false beliefs) but that doesn’t mean the underlying desire wasn’t irrational.
Feelings and desires/”wants” are not the same. It’s the difference between hedonic and preference utilitarianism. Desires are actually more similar to beliefs, as both are necessarily about something (the thing which we believe or desire), whereas feelings can often just be had, without them being about anything. E.g. you can simply feel happy without being happy about something specific. (Philosophers call mental states that are about something “intentional states” or “propositional attitudes”.)
Moreover, sets of desires, just like sets of beliefs, can be irrational (“inconsistent”). For example, if you want x to be true and also want not-x to be true. That’s irrational, just like believing x while also believing not-x. A more complex example from utility theory: If P describes your degrees of belief in various propositions, and U describes your degrees of desire that various proposition are true, and P(A and B)=0, then P(A or B)U(A or B)=P(A)U(A)+P(B)U(B). In other words, if you believe two propositions to be mutually exclusive, your expected desire for their disjunction should equal the sum of your expected desires for the individual propositions, a form of weighted average.