In the fields of the struggle for production and scientific experiment, humanity makes constant progress and nature undergoes constant change, they never remain at the same level. Therefore people have to go on discovering, inventing, creating and advancing. Ideas of stagnation, pessimism, and complacency are all wrong. They are wrong because they agree neither with the historical facts of social development, nor with the facts of nature so far known to us, as revealed in the history of celestial bodies, the earth, life, and other natural phenomena,’
