Whether or not one has memorized refresh, you are able to cast it -- and your auto-mem function will memorize another spell you have used in that slot (i.e. blindness).
If Rorc's explanation wasn't comprehensive enough, check out HELP DIVINE next time you're logged on. It explains all the details and gives examples. To see what other spells you have that might be divine, use HELP SPELL (spell name), and if it is divine, like refresh, it will say so in the help file.
Refresh is a divine spell,
Refresh is a divine spell, as such you can cast it by using another spell of the same circle.
__________________________~Rorc
If Rorc's explanation wasn't
If Rorc's explanation wasn't comprehensive enough, check out HELP DIVINE next time you're logged on. It explains all the details and gives examples. To see what other spells you have that might be divine, use HELP SPELL (spell name), and if it is divine, like refresh, it will say so in the help file.