Speculates as to whether they never cease? (7)
I believe the answer is:
wonders
'speculates' is the definition.
(wondering is a kind of speculating)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for wonders that I've seen before include "Marvels - there used to be seven of them in the world" , "Prodigies, miracles" , "Questons, marvels" , "Questions, marvels" , "Curiosities" .)