The idea you should place at the centre of your life can be expressed by a single word: light

"Learn to nurture a central thought, a nucleus, a focus around which everything else will order itself. Several circles may form around this nucleus, but at the centre there must be a single thought. Only then do you give meaning and consistency to your life. There is nothing to stop you having a head full of ideas and plans, but something solid has to be built from a central point.

Not many men and women get up in the morning with a basic idea that will guide their activity and behaviour throughout the day. Most people, from the time they wake up, rush around in all directions. They go out, they come back, and in the evening they go to bed exhausted, only to start all over again the next day; they may have other thoughts, but all just as chaotic. If at last they decide to be occupied and guided by an idea, then forces they are not even aware of but which are present in their subconscious, in the cells of their body, will awaken and align themselves with their efforts, and they will feel enlightened, helped and guided. The idea you should place at the centre of your life can be expressed by a single word: light."