The issues discussed in the last chapter concerned in the main what might be called the practical aspect of the conception of oneself as the centre of the universe. But the conception has of course also a theoretical, or epistemological, aspect which comes to a head in difficulties about solipsism. Simone Weil always thought of these aspects as essentially intertwined. The following striking remark is an entry in a notebook made at the very end of her life.

I had occasion to discuss solipsism – the most extreme form of a “subjectivist theory of cognition” – in Chapter 3. It will be remembered that as early as her treatment of it in Lectures on Philosophy she had emphasized the importance of action: the quasigeometrical structure and order involved in even the most primitive form of bodily activity is required if anything – including one's very sensations themselves – is to be a possible object of knowledge.