The baseball cap belonged to Grenson, a friend of mine at Oxford. He owned very few books and I never saw him in the library. He was working on a PhD in Logic and all he had to do was think, as he told me, just sit and think and write. This was an enviable position to be in, I always said. He could do this anywhere, unencumbered by books or tangles of footnotes. He could sit by the canal, for example, with his laptop, working through the logical structure of sentences and scribbling notes, wearing his cap. I remember very clearly the little spot by the canal where he used to sit on sunny days. I’d join him and we’d analyse a film we’d seen, or we’d talk about a woman he was pursuing. It was always a question of uncovering the implicit rules of the situation and following them. Every sphere of life had its explicit and implicit rules, and in every case the task was to identify what rules were operating and behave accordingly. And just as one could not simply choose to speak and communicate outside the rules of grammar, without making grammatical mistakes that impede communication and lead to misunderstandings, so there was no way to simply sidestep the rules and laws of interpersonal behaviour.
I always thought that this view of things, of a world structured according to manifold rules and laws, was a great imaginative construct on Grenson's part. It suited him, and pleased him, to think of the world in this way, to act and behave in a world so structured. No doubt he would say that the world really is like this, it really is structured by rules and laws, and his view simply reflected this fact, just as Leibniz might say the world is really composed of monads. But just as Leibniz's system is now thought of primarily as a fantastic imaginative construct, almost a work of art like Joyce's Wake, so Grenson's picture of the world as a network of rules can likewise be seen as, in fact, the web spun by his own imagination and expressing his soul. Most of our ideas, whatever philosophical rigour they appear to exhibit, are also always webs spun by our imagination and expressing our own peculiar form of life. All the great philosophical systems shine forth as imaginative and aesthetic constructions long after their truth content disappears or at least dwindles. The great systems, whether it be Plato or Hegel, but also more modest systems, such as Grenson's, are in fact, independent of their truth, lattice structures which conduct flows of psychological and affective energy, great machines which we plug into and from which we derive cerebral and emotional pleasure.