ThatsItImOut states that he is a optimist because previous pessimism has been proved wrong before. But statistics learns that previous results do not say anything about the chances of anything happening in the future.

Let me give you an example: Whenever you roll dice the chance to hit a "6" are 1 in 6. If you have rolled the dice hunderds of times before without hitting one single "6" you are inclined to believe that that has some influence on this time you will roll (Perhaps thinking that it has to finally be time for a "6"), but statistics learns it hasn't. The chance to hit a "6" still is 1 in 6.

This, to me, debunks stories that "we have seen pessimism not work before, therefore now I quit being a pessimist."

I see your point but I would examine the die to see if had been altered.  Optimism/pessimism is not just a straight course in statistics though.  Believing you can win often helps you do so.  Its not Faith or God or Luck, just the positive image of success in your mind can drive you.  And in complex scenarios positive thinking is crucial.  I have a duality of imagining whats the worst/best thing that could happen then forcing the best to be so.

I said what because I read your post about the bomb on the airplane and could not get your message.

Statistically you are right odds are odds and they are not changed by history.

Your point is well taken. However, the point of criticizing pessimism is not, I think, that it has failed to produce results till now but rather that pessimism usually rears its head as a fear, not as a rational prediction. Therefore, we should pay attention to the flashing red light but we should not try to interpret it as a logical argument.

If you look in various fields there have been many "doom lies ahead" arguments. I recall reading a book predicting a financial meltdown around the year 1990. EDN magazine in the early 1980s predicted a crisis in engineering as there would not be sufficient engineers to design electronic products. This was largely solved by the vast scale of chip integration which made it easier to build products with fewer engineers. A book about future problems I picked up written in the fifties predicted a shortage of chemical engineers (but totally neglected future problems with pollution). Currently some economists are predicting an economic meltdown due to the extraordinarily high debts we have run up.

It is not that any of these arguments were deeply flawed. It is just very difficult to predict the future. Also, things generally happen to mitigate the imagined problem. Personally, I don't agree with the doomers. Technically, it does seem clear that we are at or near peak oil production. It is the result that is in question. I think we will muddle through though there may be some hard times ahead.