The astrologer contemplates his arcane books and a device for calculating the position of the planets on a given date, but death hold a skull before him, seeming to say: contemplate this instead. A skull was a common memento mori during the middle ages. Holbein's illustration from the Dance of Death may be a subtle critique of astrological science in that the astrologer purports to be able to predict the future, yet is ignorant of his own impending doom.
Next: The Miser
The Dance of Death is an important allegory commenting on human mortality and the passing transience of life. It depicts Death as a fairly jovial skeleton armed with a scythe, who invites his victims to a dance which invariably ends in their demise. The point of the allegory is that no one can refuse its invitation to the dance: hgh church officials, kings or paupers, all must dance and eventually die.