Open space for the indefinite

I've recently encountered two times this quote from Lewis Caroll taken in Alice in Wonderland:

'There is no use in trying', said Alice; 'one can't believe impossible things.' 'I dare say you haven't had much practice,' said the Queen. 'When I was your age, I always did it for half an hour a day. Why, sometimes I've believed as many as six impossible things before breakfast.'

Why do I blog this? One of the occurrence with it was in "After Method: Mess in Social Science Research (International Library of Sociology)" (John Law), where the author use it to stress the need to have "metaphors and images for what is impossible or barely possible, unthinkable or almost unthinkable." His claim is that it's important to open space for the indefinite.

This surely seems very abstract but the practice itself of such weird exercice is intriguing in terms of the implications for foresight. In a sense, it reminds of Donald Rumsfeld matrix of known/unknown.