Pessimism, from the Latin pessimus (worst), is a state of mind which negatively colors the perception of life. Value judgments may vary dramatically between individuals, even when judgments of fact are undisputed. Always thinking negative. The most common example of this phenomenon is the "Is the glass half empty or half full?" situation. The degree in which situations like these are evaluated as something good or something bad can be described in terms of one's optimism or pessimism respectively. Throughout history, the pessimistic disposition has had effects on all major areas of thinking.
Philosophical pessimism is the similar but not identical idea that life has a negative value, or that this world is as bad as it could possibly be. It has also been noted by many philosophers that pessimism is not a disposition as the term commonly connotes. Instead, it is a cogent philosophy that directly challenges the notion of progress and what may be considered the faith-based claims of optimism.
