This paper aims to discuss at a fundamental level the observation that the world can be seen as grey, or uncertain.
Attention is given first to arguments that suggest that the future should be seen as totally unknown, or black. Reasons are given for dismissing these arguments, and then consideration is given to fundamental causes of uncertainty which prevent the world being white or totally known.
The treatment is at a fundamental level that has little bearing on current practical means of dealing with uncertainty, but it is claimed that consideration of fundamentals is often unexpectedly rewarding and therefore worth pursuing.
There are probably few practical implications, at least in the short term.
The viewpoints appear to have received little previous notice.
