Today they are among the most precious things on the planet. The notebooks, the core obsession of Leonardo’s life, are what place him among the giants of science, not specific discoveries he made or new inventions he created.So what are they, exactly?We call them “notebooks,” but they are not bound like a typical notebook. Mostly they are loose sheets of paper casually gathered together and wrapped with different fabrics. Some pages are large. Others are only two or three inches square; these must be from the tiny blank notebooks he always kept tied to his belt.Leonardo went out of his way to make the notebooks difficult for any other person to read—tremendously out of his way. The main roadblock is his famous mirror-image script. His tiny writing goes backward, reading from right to left. The drawings aren’t backward, just the words.What was he thinking?Although he could draw with both hands, Leonardo remained left-handed. Was it simply easier or faster for him to write this way?
