**For Clarification**
By saying that pessimism and optimism are analogous to bad and good, what do you mean? Do you mean morality? Pleasure and pain? Usefulness? Maybe I'm trying to be too precise...do you just mean "nice things" when you say good and "not nice things" when you say bad (regardless of what that might mean to different people)?
Part I
1. It is people who are optimistic or pessimistic... It does not seem possible for trees or other inanimate objects to be one or the other... Nor, I think, arguments. (There may be arguments for good outcomes, but the argument itself is not, strictly speaking, optimistic).
Agreed. Pessimism and optimism are views about things. Being
about things, they must be had by some thing; and being views, they must be had by rational things. An optimistic or pessimistic person is a person that holds one of these views. This, incidentally, is why I think they are not analogous to "good" and "bad" since those terms are much broader and need not only apply to people. (Explain to me why this matters to our discussion, though, as I am at a loss to see what this helps establish).
2. The real question about the relative maturity or immaturity of a sad, sober, nigh-despairing state of mind is this: Is reality really sad, sober, and desperate? or is it happy, vibrant, and hopeful?... It is on this that the real issue hangs (whether this person holds a rational belief in the benevolence of the universe, or a rational belief in the nasty, brutish, and unforgiving nature of the universe).
Agreed. A view that equates a movement towards cynicism and despair as a (positive) movement towards maturity is a view of reality as the sort of thing that justifies cynicism and despair.
Part II
1.
Will anyone disagree with this statement? People who think that the world is good overall agree that there is some bad, some pain, some darkness in it; and people who believe the world is dreary over all agree that there are some islands of fleeting joy and mirth in it.
I disagree. The pessimist and the optimist think either that the world is all bad or all good, respectively. Thus, any isolated instances of joy or pain are engulfed by the overall status and movement of the cosmos, and those instances ultimately lose any meaning that could differentiate them from the badness or goodness of the cosmos. The pessimist takes seemingly good things and points out that they really aren't good, which is why you should never invite one to your child's birthday party. The optimist does the opposite, which is why he is usually not welcome at funerals. In other words, the pessimist and optimist might agree that there
seem to exist things that do not quite fit with their overall view of the cosmos; however the trademark of the pessimist or optimist is to go on and explain that these things aren't what they
seem. This is the crucial point; both the pessimist and the optimist deny the existence of good or bad, respectively, and so (if both good and bad things really do exist) create an illusion of reality.
This is why, in a pessimist's world, a movement towards darkness, futility, and despair is a movement towards maturity; it is a movement towards understanding, towards accepting the pessimist's version of reality as true.
2. You said, "we have not learned to be happy." I ask, "Is it possible to learn to be happy, or not?"
Yes, it is possible. To put it simply, we learn to be happy when we learn that we have reason to be happy. If we discover that the cosmos are a mix of good and bad but that the good will triumph over the bad, and we are on the side of the good, then we have reason to be happy. Conversely, we can learn to not be happy when we learn that there is no reason to be happy.
It is the work of discovering the true nature of the cosmos that remains to be explored.