Full Idea
If there is no other means of supporting his child, a father may give up his son as a pledge for a loan, or sell him into endurable slavery rather than let him die of want, at least on the condition that these acts may be revoked.
Gist of Idea
A man may sell his son into slavery, if the alternative is death from want
Source
Samuel Pufendorf (On the Duty of Man and Citizen [1673], II.03)
A Reaction
Shocking to us, but bear in mind 1) very large families, and 2) that to die of want was not uncommon. Even so, using your son as surety for a load is a bit startling, coming from a famous proponent of natural law.
Book Reference
Pufendorf,Samuel: 'On the Duty of Man and Citizen' [CUP 1991], p.127