This is the old conundrum, is your glass half empty or half full? which is supposed to elicit whether you are an optimist or pessimist.

The trouble with this question is that it is constrained by the fact that there is a container and by definition a boundary to your thinking.

What about a world in which there is no glass and so there are no limits to optimism or pessimism? Mere physical boundaries should not exist when it comes down to personal characteristics as the world is what you make it.

A lot of Eastern Philosophy is going on in that last paragraph which makes the whole issue of what governs are thinking open to debate.

Many suceesful (and Western) business leaders have developed the 'can do/think outside the box/paint the sky blue' thinking which has it roots in this philosophy.

One thing is certain, if you believe there to be a boundary to your thinking there will be.