[Author;s Note: This is intended to be inserted between posts 0010 and 0011.
It is not contrary to reason to prefer the destruction of the whole world to the scratching of my finger. It is not contrary to reason for me to chuse my total ruin, to prevent the least uneasiness of an Indian or person wholly unknown to me. It is not contrary to reason for me to chuse my total ruin, to prevent the least uneasiness of an Indian or person wholly unknown to me. (David Hume, A Treatise of Human Nature, Section III)
The nature of beliefs and desires that I am using in these postings owe a great deal to David Hume.
Given what we have already discussed, we can make sense of Hume's claim noted above.
We have been postulating a universe with only one being (Alph) having only one desire (to gather stones). To understand Hume's quote, let us change this one desire to an aversion to being in pain. This is all the agent cares about.
In this, I have already provided an example very much like that of the second claim that Hume made above. I have discussed a case in which Alph has only one desire - a desire that the planet Pandora B (a planet that will contain only plant life; no animals) come into existence.
In a situation where Alph could bring this planet into existence by pushing a button that would destroy himself, he has a reason to push the button and no reason not to. In this case, Alph is choosing his own destruction to realize a state of affairs in which the planet Pandora B exists.
To explain the first claim that Hume made, let's put Alph in a situation where he has two options. He knows that he is about to get a scratch on his finger. However, he can avoid this scratch by an action that will bring about the destruction of the world.
We will need to stipulate that the destruction of the world will cause Alph no pain - and Alph knows this. If it did, then Alph's aversion to pain would give him a reason to avoid the destruction of the whole world.
It is also important to add that Alph, in this case, has no desire that can only be fulfilled if the world continues to exist. If he had such a concern, then that would give him reason to avoid the destruction of the world.
We must even take from Alph the desire to gather stones since, if the world was destroyed, Alph would no longer be able to keep or make true the proposition, "I am gathering stones." Thus, having such a desire gives him a reason to avoid bringing about the destruction of the world.
All we have is Alph with an aversion to pain, and pain that can be avoided by (painlessly) destroying the world.
In such a situation, Alph has no reason to prevent the destruction of the world in order to prevent even a mild pain that would result from a scratch on his finger.
There are, according to Hume, only two roles for reason in directing action.
First, When a passion, such as hope or fear, grief or joy, despair or security, is founded on the supposition or the existence of objects, which really do not exist. Secondly, When in exerting any passion in action, we chuse means insufficient for the designed end, and deceive ourselves in our judgment of causes and effects. Where a passion is neither founded on false suppositions, nor chuses means insufficient for the end, the understanding can neither justify nor condemn it.
Let me put this quote into the language I am using for these posts.
First, reason can tell an agent with a desire that P whether P is true in any state of affairs S. If it is, then reason informs the agent that she has motivation to bring about S.
For example, let us assume that the destruction of the world would, in fact, cause Alph to experience pain, at least for a short while. When reason informs Alph of this fact, Alph would come to be averse to destroying the world - but only because Alph has an aversion to the pain that he would experience as a part of that destruction.
Second, reason can tell an agent with a desire that P that an act Q will realize S, where P is true in S. When this happens, then reason informs the agent that she has motivation to realize Q.
In other words, reason can inform Alph that the pain that would come from a scratch on his finger can be avoided if he performs an action that will (painlessly, in this case) destroy the world. If this is the case, the agent will wish to perform that action. Yet, here, too, it is the agent's aversion to pain that provides the motivation.
I will argue later that, contrary to Hume, there is a third sense in which a passion can be judged unreasonable. However, this will only happen when passions come into conflict, and agents have the capacity to choose whether or not to have (or to create in others) various passions. Consequently, it is not a fitting discussion for our current situation where we have an agent with only one desire. We will return to this possibility after we have introduced more desires, more agents, and the possibility of choosing desires.