Science, the proud son of the era and the crystallization of man's wisdom, is inlaid in the crown of our times like a lustrous and brilliant pearl. Social science discloses to mankind the general law governing the development of society and leads it in marching forward to the higher stages of social system - socialist society and communist society. Natural science creates for mankind tremendous productive forces like miracles, enabling the human race to live a life in fairyland. Who is (...) there who does not praise the power of science and refuses to admit that science is the great force pushing history forward? Who is there that dares openly to set up forbidden zones in science, thus serving as an executioner to strangle science? In our times, people who dare openly to do this, perhaps, are increasingly few. However, this does not mean that science can completely extricate itself from disaster. Science has to pay dearly for every step of exploration and has to undergo a stern struggle for it. Science is an undertaking that is most creative and filled with the spirit of innovation. It openly declares that it will wage an irreconcilable struggle against all the old stuff which is reactionary, dark, ignorant and superstitious. Because of this, it is bound to suffer bans and buffets from the reactionary forces. Science has no forbidden zone! This is a call of reason; but there are forbidden zones in science, and that is what we see in the picture of history and reality. What are the forbidden zones? And how should we destroy the forbidden zones and set science free? For many years Lin Biao and the "gang of four" brought terrible disasters to science. In consequence, the aforementioned question is sharply raised before us, requiring us to deal with it strictly and try to resolve it correctly. (shrink)