Kant on Ingratitude

In his Lectures on Ethics, Kant says that ingratitude is among the vices that “are the essence of vileness and wickedness.” He adds, “It is inhuman to hate and persecute one from whom we have reaped a benefit, and if such conduct were the rule it would cause untold harm. Men would then be afraid to do good to anyone lest they should receive evil in return for their good.” He argues too that a good man might deliberately refuse benefits offered so as to avoid the obligations it imposes on him.