A cliff in a dream often marks a decision point where the next step carries real risk -- a choice you can't easily walk back from once it's made. Standing at the edge can mirror hesitation about committing, while the fear of falling usually names anxiety about what happens if the choice doesn't go the way you hope.
The astrologer is able to control the actions of the stars if he knows the influx of their nature; is quite likely that he can modify the action before it happens. - Ptolomeus