Definition of an optimism and definition of a pessimist

A quote about optimism and pessimism:

‘An optimist thinks that we’re moving towards the best of all possible worlds. A pessimist thinks that we’ve already arrived.’

This quotation about optimism and pessimism came to me in June 2013  while I was thinking of ideas around the subjects of optimism and pessimism in general.

The quotation is all my own work, however a quick check of quotes on the internet about optimists and pessimists inevitably revealed that a similar expression already existed. Here it is:

“The optimist proclaims that we live in the best of all possible worlds; and the pessimist fears this is true.”
This quote is by James Branch Cabell from his book The Silver Stallion.

Both quotations include the phrase ‘the best of all possible worlds’. I think that in both cases this phrase is absolutely central, and without it the quotation can’t exist. In fact, in my case at least, it was the act of thinking about this phrase as it applies to optimists that made me think of the way the phrase might apply to pessimists.

The main difference between my version of the expression and James Branch Cabell’s version is that my version looks to the future while Cabell’s looks to the present. My quote looks to the future because it’s my opinion that optimism and pessimism are qualities that are directed towards the future.