Books that resonate with the idea “The calmer you are, the clearer you think”

I'm looking for book recommendations that explore the concept of calmness and clarity of thought.

I’m trying to overcome a few addictions hence I'm interested in books that emphasize how maintaining a calm and composed mindset can lead to better decision-making and clearer thinking.
Whether it's fiction, non-fiction or philosophical texts, I'd love to hear your suggestions.