What Is a Desire?

I am rebuilding my desirism wiki. I am doing so by submitting here (for your review and comment) the text that I will be adding over there.

Today's topic: What is a desire?

This topic will take a lot of work. I am hoping that there are people out there who would not mind sharing some of their special knowledge - providing me with references that supports, refutes, or refines the points made below.

Beliefs and desires are the proximate causes of intentional action. When you ask why somebody did something, you expect an answer that provides you with the relevant beliefs and desires that explain that action. Not only must it explain that specific action, but it must make that action consistent with other actions that the agent has performed and be able to predict potential future actions.

"Why did you choose to invest in that articular mutual fund."

The answer may involve wanting a high rate of return and believing that the mutual fund will provide it. The answer might include some interest in social responsibility. Perhaps a family member works for the company and the investor wanted to support her, or the investor values investing in developing economies and believes that the mutual fund focuses on those types of investments.

It is important to note that beliefs and desires explain and predict observable events in the real world. While there is some dispute about the merits of this form of explanation. However, in our every-day world, we currently have nothing better.

So, what are these entities that explain intentional action?

Beliefs and desires are mental states. They are properties of the mind-brain - physical properties of physical objects in the physical universe.

Beliefs and desires are functional properties - properties that describe what is going on (or can go on) within an object. In this, the mind-brain is much like a computer, storing data (beliefs) that might or might not be true, assigning value to certain states, and using that data and those values to determine output (behavior).

Beliefs and desires are known as "propositional attitudes". This means that they describe attitudes towards propositions.

A proposition, in turn, is the meaning component of a sentence. It is a statement capable of being true or false. “Jenny is visiting her mother in Iowa” is a proposition. It is a statement. It might be true. It might be false. "Jenny is in Iowa visiting her mother" is a different sentence, but it is the same proposition. It says the same thing.

A belief is the attitude that a proposition is true.

I will often express a belief in the form, "A believes that P", where "P" is some proposition. A person who believes that P will plan his actions for a universe in which "P" is true. If "P" happens to be false, this will usually have an adverse effect on the agent's success.

So, if I believe that Jenny is in Iowa visiting her mother, and I desire to talk to Jenny, and I know her mother's phone number, then I should conclude that I can reach Jenny by calling that number and I have a motivating reason to call that number. If that belief is false, I am wasting my time calling that number.

A desire is a motivational drive to make a proposition true or to keep the proposition true.

If I want Jenny to visit her mother in Iowa, this gives me a motivating reason to act to make the proposition, "Jenny is visiting her mother in Iowa" true. I may try to persuade Jenny to visit her mother. I may purchase her airplane ticket. What I am looking for is an action - given my beliefs - that is likely to make it true that Jenny is visiting her mother.

It is important to stress here that what matters is the objective satisfaction of a desire - creating a state where the proposition that is desired is objectively true in the real world. (Note: This is a state that I have called in my previous writing "desire fulfillment" - yet it seems that the professional academic literature on desires has settled on the more cumbersome phrase, "objective desire satisfaction").

This is to be understood in contrast with "subjective desire satisfaction" - which is the (potentially false) belief that a desired proposition is true.

A parent may believe that his child is safe at a friend's house. At that moment, unknown to the parent, she may be the victim of a violent attack. The parent's desire that their child is safe is subjectively satisfied (he believes it is true) but not objectively satisfied (true in fact). Of the two, intentional action aims for objective satisfaction (making a proposition true in fact), not subjective satisfaction (making oneself believe that it is true).

Each person is motivated only by his or her own desires (and beliefs).

This is a truth that egoists note, but that they do not understand. Egoists note that agents always act solely on their own desires. They then confuse this with the claim that everybody acts for their own benefit. When challenged by a case in which a person acts to benefit others, they will answer, "She is still doing what she wants." This is true. However, if what she wants is the well-being of another person, this is not egoistic selfishness. It is the very definition of altruism.

Even if it were possible for my desires to motivate your actions – for my desires to cause your limbs to move and to realize states of affairs that I am motivated to bring about – those actions would not be your actions. An action can not, at the same time, be your action and come from my mental states. If those actions come from my mental states (or the degree to which they come from my mental states), they are my actions, not yours.

A mind control device that would allow me to take over your body and commit a crime would not make you guilty of that crime. Because the crime did not spring from your beliefs and desires, it is not you action. It is my action. I am the person to be held responsible, not you.

When we morally evaluate an action, we are actually evaluating the mental states behind that action. If I am controlling your body, the causal states are mine, not yours. It is my mental states that are being evaluated, not your physical action.