Leonardo da Vinci and his Notebooks

[Leonardo's notebooks]

I have already mentioned in the earlier blog post that one of the reasons why Leonardo wrote in the mirror imaged manner was due to the fact that it was kinetically natural and convenient for a left handed person as he was.

The notebooks may have been used to sketch out his thoughts with the words and the images, so he can re-read them, in case he has forgotten, so it was not in the finalized form.
Leonardo entrusted the notebooks to Melzi to be possibly edited and published as a sort of an encyclopedia.
The content has not always to do with the "secret" discovery nor the important ideas  for the inventions. It was used as the simple and elaborated memos. It contained the personal accounting information and the complaint about his adopted son, Salai, as well.

I feel that he was not worried about the contents being read, understood, or stolen, for not many had the genius/intelligence/imagination to keep up with his ideas. It was rather that the "misunderstanding" and the "misconception" of the content may have made him weary.

It is true that Leonardo's notebooks contained the images of the new weapons, the architectural renderings, and the engineering ideas. Those were not in the final form. In order for many of these larger projects to be carried out and manifested, he needed the backing from the people like the Duke who can supply the man power and provide the financial support, etc. To ask the Duke for such help, Leonardo needed to convince or persuade the Duke, and it had to be in the Duke's advantage; therefore, the presentation was crucial. The reason why Leonardo kept these notebooks-journals-memos to himself is very simple: the content is not in the final, complete, articulated form.
For someone to have the access to his unpolished, 'premature' writings would possibly be lead to the misunderstanding... especially if the one who is reading lacks the imagination and the intelligence.
Any smart writers would not share the plot of the thriller prematurely.
Not many comedians would tell a unpolished joke. It is normal to keep the ideas from the general public until it can be organized and made presentable. Even with such careful presentation, there are no guarantee that people would not misunderstand it.

{I usually do not show my sketches or my notebooks (There are many!) to the people. It is not because I am secretive or being afraid that some might be inclined to steal my ideas, etc. I just don't want my ideas to be prematurely disclosed and misunderstood.}

He may have hid his notes because it was not written well. Some scholars feel that Leonardo was not necessary gifted with the words. And they feel that ... (to be continued...)