Will Young: Telos
“The ancient Greek philosophers described a concept of telos, which refers to the inherent purpose of something. For instance, the telos of a mask is to cover your mouth and nose to prevent the spread of a dangerous pathogen. You can use a mask for other things if you like, such as adorning your neck, but that is not fulfilling its telos. With my education in the medical sciences and the patterns of reasoning I had been developing throughout my education, I felt that my telos had to be medicine.