They think if they know the word, they know the thing itself. The third law is that words can never say all about anything and that definitions of words can continue indefinitely. Epistemology is the study of knowledge. Knowledge ranges from absolute falseness to absolute truth. There exist probability logics for dealing with this infinite range of truth-values.
Imagination possesses the lowest degree of truth-value, mere fantasy.
But anything that can be conceived by a human being is possible. Fantasy has the lowest likelihood of any human thought of being true. Suppositions or guesses are a step up from fantasy. Perhaps because subconscious thought processes based on other knowledge are involved in guesswork, guesses are more likely to be true than mere fantasy. They are also better statistically, i.e., more likely to be true, than random choices.