One cannot know that blue is a colour, for example, if the object of that knowledge is something other than that blue is a colour.
In both cases cited by Jackson, an epistemic subject A appears to have no access to particular items of knowledge about a subject B: A cannot know that B has an experience of a particular quality Q on certain occasions.
Many take it to be obvious that a person cannot know that she now has a blue experience unless her blue experience plays a prominent causal role in the formation of her belief at issue.
This means that a player cannot know that her opponent will not choose an action at a state \(w\) which is deemed rational (according to some choice rule).
For example, we cannot know that the nearby bird is a finch rather than a finch lookalike made by skilled aliens.
So given the sensitivity condition, George cannot know that he is not in such a scenario.
Recall that having a cautious belief means that a player cannot know which options her opponent(s) will pick[15] from a set of choice-worthy options (in the above game, if Ann knows that Bob is choosing \(l\), then both \ u\) and \(d\) are "choice-worthy", so Bob cannot know that Ann is choosing \ u\)).
That is, observers cannot know if an entity has dropped a bag unless they knew that the entity had a bag in the first place.
Until this is done we cannot know whether a SNP or haplotype that is associated with a phenotype is a functional variant or merely a nearby marker.
It is important to know that statistics cannot provide a simple substitute for clinical judgment (Jeckel et al. 2007; Rothman et al. 2008; Szklo and Nieto 2007).
Every schoolboy knows (or should know) that government cannot "go broke" like a private business.
