Peddlers of verbiage – and there are some – endlessly make vacuous pronouncements about what they call the importance of practice and the uselessness and danger of theory. There is only one thing to say on this. Imagine any sequence of the most useful, excellent, and considered facts that you possibly can. Can you imagine that the theoretical order does not contain a sequence of ideas and truths that corresponds exactly to your practical chain? Unless you have entirely lost your reason, you will see that the one follows from the other or, better, precedes it. What, pray, is theory unless it is that connected sequence of truths that you might not be able to see until it has been made real but which someone has to have seen, unless of course everyone proceeds on the basis of not knowing what they are doing?