 At other times Berlin seems to advance what amounts almost to a theory of natural law, albeit in minimalist, empirical dress. In such cases he suggests that there are certain unvarying features of human beings, as they have been constituted throughout recorded history, that make certain values important, or even necessary, to them. Values, then, would be beliefs about what it is good to be and do – about what sort of life, what sort of character, what sort of actions, what state of being it is desirable, given human nature, for us to aspire to. This view of the origin of values also comes into play in Berlin’s defence of the value of liberty, when he suggests that the freedom to think, to enquire, to imagine, and above all to choose, without constraint or fear, is valuable because human beings need such mental freedom; to deny it to them is a denial of their nature, imposes an intolerable burden, and at the extreme entirely dehumanises them.