A statement containing two opposite but true ideas is called_______

Paradox
- It is apparently a  self-contradictory statement, the underlying meaning of which is revealed only by careful scrutiny.
- The purpose of a paradox is to arrest attention and provoke fresh thought.

Example: 
- The statement “Less is more” is an example.
- Francis Bacon’s saying, “The most corrected copies are commonly the least correct,” is an earlier literary example.
- In George Orwell’s anti-utopian satire Animal Farm (1945), the first commandment of the animals’ commune is revised into a witty paradox: “All animals are equal, but some animals are more equal than others.

Source: Britannica.com