 In order to deny that Blockhead is a logical possibility, it seems that what needs to be denied is the commonly accepted link between conceivability and logical possibility: it certainly seems that Blockhead is conceivable, and so, if (properly circumscribed) conceivability is sufficient for logical possibility, then it seems that we have good reason to accept that Blockhead is a logical possibility. Since it would take us too far away from our present concerns to explore this issue properly, we merely note that it remains a controversial question whether (properly circumscribed) conceivability is sufficient for logical possibility. (For further discussion of this issue, see Crooke (2002).)