A Keynesian analysis of forced saving

.. if the community has great need of a large sum of money for a war or for the ransom of its prince from captivity... it might raise it by altering the money, and this would not be contrary to nature or usurious... in this arrangement about all the conditions desirable for such a levy seem to be combined; it brings in a large revenue in a short time, it is very easy to collect and assess without the services of many officials, and it involves little expense or opportunity for fraud by the collectors. Indeed, no other more equitable or proportional plan can be imagined; for he who has more pays more, and being relatively less felt, it is more tolerable without danger of rebellion and complaint by the people. It is also very general, for neither cleric nor noble can escape it.