Each has a main figure in the foreground with two subsidiary ones behind, both are night scenes and show old men engaged in scientific research.

[1] The painting shows an old man who is thought to be a philosopher or a pilgrim, examining a collection of human bones in a lamp-lit cave.

Two smaller men, or boys, dressed as pilgrims (as identified by the scallop shells in their hats: the emblem of St James) seem to be approaching him.

He is surrounded by symbols of the ephemeral nature of the human condition which include the skeleton, a lamp that will burn all its fuel, the moon which has to be reborn every four weeks and an hour glass.

The preoccupation of the philosopher and trepidation of the two pilgrims may be a reflection on concerns about the new scientific understanding and enlightenment at the time Wright lived.