Meditation In A Toolshed is #6 in Part II of God In The Dock -- it is about a lightbeam and the difference of perspective from looking at the lightbeam and looking along the lightbeam. It is a critique of those who would be critical of others using "looking at" thinking without experiencing "looking along" knowledge. See God In The Dock, Meditation, Metaphor, Essays, EssayIndex

The idea of looking at versus looking along appears in different forms repeatedly in Lewis. It is the same idea as thinking versus reflecting on one's thinking about something. When you are reflecting on your thinking about something you are no longer thinking about it. It is also related to the idea that something can be intimately present to you and you not being fully aware of it as the analogies of looking through the window, reading with your eyes, the fish not really experiencing the water and Lewis applies this finally in Miracles to our not being immediately aware of the stupendous fact of the Supernatural. It is related to Lewis' point that human rationality is a supernatural reality, if you will the First Miracle.