Positivism is a philosophical and scientific movement that emerged in the 19th century. It is based on the belief that knowledge can only be acquired through observation and experimentation, and that all phenomena can be explained by natural laws. The term 'CERTAINTY' is often associated with positivism, as it emphasizes the importance of having a firm foundation for knowledge. This is because positivism holds that knowledge should be based on facts and evidence, rather than on faith or intuition.