 When it is a matter of perception, in the Mueller-Lyer figure the line with the arrowheads pointing inward appears longer than the one with them pointing outward even if you know it is not really longer. To some people at least, in the Monty Hall example it seems that there is a 50-50 chance that the grand prize is behind either of the two doors that are left unopened after Monty has opened one of them, even though they know that the probability it is behind the door the contestant did not choose is 2/3 (see Russell 2010: 464, for the Monty Hall example). So intuitions are a type of appearing; physical and philosophical intuitions have this in common. George Bealer characterizes a rational intuition as an intellectual seeming that some proposition is necessarily, or possibly, true (Bealer 1998: 207–208). He contrasts this with the physical intuition that a house undermined will fall which is not about what is necessarily or possibly true. Also, philosophical intuitions are based solely on understanding the proposition which is their object while physical intuitions are based on understanding something about the physical world. Bealer contrasts intuitions with “judgments, guesses, and hunches” (1998: 210–211), common sense, belief, and even an inclination to believe (1998: 208–209). And, of course, they are not just “gut feelings”, which are not based solely on understanding some proposition,