A letter concerning toleration; concerning civil government, second essay; an essay concerning human understanding - Locke, John 1632-1704; Berkeley, George 1685-1753; Hume, David 1711-1776 (Encyclopaedia Britannica, 1952)
Enth. 1.: Berkeley, George: The principles of human knowledge. Enth. 2.: Hume, David: An enquiry concerning human understanding