Stoicism is an ethical system founded on the principle that everything happens for a reason, and that reason is inherent within each individual. The Stoics believed that perception is the basis of true knowledge. In logic, their comprehensive presentation of the topic is derived from perception, yielding not only the judgment that knowledge is possible but also that certainty is possible, on the analogy of the incorrigibility of perceptual experience. Zeno of Citium, the founder of this school of thought, believed that virtue alone is sufficient to lead a good life and ensure happiness, and using reason we must accept things the way they are as nature is the only reality.
The rise of stoicism coincided with the fall of Greek political and cultural systems and the rise of the Roman era. The Romans – not keen on accepting philosophical conducts – found stoicism befitting of their cultural and ethical practices. Hence, stoicism was adopted by many thinkers and became the prevailing and widely accepted philosophy of the Roman Empire.