Montesquieu
 

XXVI.5 A case in which one can judge by the principles of civil law, by modifying the principles of natural law

A law of Athens obli­ged chil­dren to feed their fathers who had fal­len into indi­gence1 ; it excep­ted those who were born to a cour­te­san,2 those whose father had expo­sed their chas­tity through an igno­mi­nious com­merce, and those to whom he had taught no trade by which to earn their living.3

The law consi­de­red that, in the first case, the father being uncer­tain, he had made his natu­ral obli­ga­tion dubious ; that in the second he had defi­led the life he had given, and done as much harm as he could do to his chil­dren by depri­ving them of their cha­rac­ter ; in the third, that he made unbea­ra­ble to them a life they had such dif­fi­culty sup­por­ting. The law was no lon­ger seeing the father and son as any­thing more than two citi­zens, and was deci­ding now based only on poli­ti­cal and civil points of view ; it was consi­de­rin g that in a good repu­blic there must above all be mora­lity. I do believe that the law of Solon was right in the first two cases, whe­ther nature lea­ves the son uncer­tain who his father is, or nature even seems to require that he not own him ; but we can hardly approve him in the third, where the father had vio­la­ted only a civil obli­ga­tion.

On pain of infamy ; another, on pain of prison.

Plutarch, Life of Solon.

Plutarch, Life of Solon, and Galen, in Adhortatio ad artes addiscendas, ch. viii.