Stoic philosophy is an ancient school of thought that emphasizes the development of self-control and inner peace. Zeno, a Greek philosopher from the 4th century BC, is considered to be the founder of Stoicism. CATO, another 4th century BC philosopher, was a Roman statesman and a major proponent of Stoic philosophy. Epictetus, a Greek philosopher from the 1st century AD, was a major exponent of Stoic philosophy and wrote extensively on the subject.