Malcolm MacIntosh is a Scottish scientist who wrote a book called "Hopes For The Future", claiming it is the future of American science.
Events of Red Dead Redemption 2
Malcolm MacIntosh is seen in Annesburg, trying to sell his book. If the player wishes, they can buy it from him. He also preaches the importance of using science and knowledge for good. If the player opens the book, returns to his location, and interacts with him, the player and Malcolm MacIntosh will talk about his ideas for the next chapter. The player then wishes him well. He then says thank you a few times as the player leaves. After a bit, he may leave after a few words.