 Perhaps all that’s required to implicitly believe something is that the relevant content be swiftly derivable from something one explicitly believes (Dennett 1978, 1987). Thus, in the planets case, we may say that you believe explicitly that the number of planets is 8 and only implicitly that the number of planets is less than 9, less than 10, etc. Of course, if swift derivability is the criterion, then although there may be a sharp line between explicit and implicit beliefs (depending on whether the representation is stored or not), there will not be a sharp line between what one believes implicitly and what, though derivable from one’s beliefs, one does not actually believe, since swiftness is a matter of degree (see Field 1978; Lycan 1986).