The work dated 1644, as can be read on the parchment roll held in the mathematician's right hand, has been traced back to Ribera because it can be assimilated to other works by the painter, depicting half figures of philosophers, saints and beggars, similarly represented frontally with the relative attributes in the foreground. Characteristic of the author is in fact the high expressive intensity, given through the explicit realism of details such as the wrinkles of the face and the skilful rendering of the beard and hair.