The Roman philosophy of stoicism promoted the idea that calm and collected thoughts and mindsets were crucial for good leadership, since "hotheaded" irrationality was detrimental to society.
Del Verrocchio was Leonardo Da Vinci's teacher or master artist. He retired because he thinks he could not paint as well as Da Vinci. Though Del Verrocchio, Da Vinci would have been exposed to both theoretical training and vast variety of technical skills.
Middle passage is the answer................