William Godwin did not philosophically address the question of debt obligations, although he often had many. Perhaps this helps to explain the omission. It’s very likely that Godwin would deny that there is such a thing as the obligation to repay debts, and his creditors wouldn’t have liked that.
Descartes divided the mind up into two faculties: intellect and will. The intellect gathers up data from the world and presents the mind with various potential beliefs that it might endorse; the will then chooses which of them to endorse. We can look at the evidence for or against a particular belief, but the final choice about what to believe remains a matter of choice. This raises the question of the ‘ethics of belief,’ the title of an essay by the mathematician William K. Clifford, in which he argued that ‘it is wrong always, everywhere, and for anyone, to believe anything upon insufficient evidence.’