Humans can promise; to be able to promise we must forget to create space for new promises. If we didn’t forget there would be no present; we must forget some of the past to know the present.
When we promise we actively form a memory of the promise. This requires three things: “I want” to make the promise, a will to form promises and a will to act on the promise. This is predicated on the ability to differentiate between necessary and accidental, causality, anticipating a possible future and fixing a goal. Therefore, humans must be calculable, regular, necessary and future.
In pre-history humans became regular, lived like among like and were predictable; thus, forming the “morality of custom”. This process eventually led to the sovereign individual as the standard of value and a burden of responsibility called conscience.