Pyrrho of Elis was a Greek philosopher from the 4th century BCE who is considered the first Sceptic philosopher. He believed that humans could never know the truth and could only grasp appearances. Pyrrho rejected education and the possibility of knowledge, believing everything was unmeasurable and that people were incapable of telling the truth. He taught that happiness could be achieved by rejecting the search for knowledge and avoiding stress and emotion. Pyrrho's teachings on the impossibility of knowledge were a thorough exposition of non-cognitivism and had ethical implications compared to Stoic and Epicurean ideals of tranquility.