To begin with, Lakatos; said that sceptics believe that science is really no different than any other belief system, in his words,. "Scepticism regards scientific theories as just one family of beliefs which rank equally, epistemologically, with the thousands of other belief systems. Skeptical theories; he explained, are noted by these two properties.

(1) One belief system is no more "right" than. any other belief system, though some may have more might.

(2)There may be changes ln belief systems, but no progress..

Lakatos' prime example of scepticism is Feyerabend's "Epistemological Anarchism", which teaches that any belief system, including those of his opponents, as free to grow and influence any other belief system, but none has epistemological superiority.

The sceptic thus denies the possibility of appraising scientific theories. As a result they believe that scientific historians reconstruct the history of science according to their own personal bias, that the Copernican revolution, the rise of modern atomism, and the gradual emergence of the wave theory of light occurred only because some thinkers either decided not to be bound by obvious methodological rules, or because they unwittingly broke them. It is not that sceptics reject progress, they refuse to define what it is. As a result, they state that criteria for the appraisal of scientific theories are not only impossible, but dangerous, they act to impede scientific progress by reducing the freedom of thought.

Strangely enough, the best supporting evidence for this theory can be derived from the Demarcationists themselves. Rules for demarcation, sceptics are quick to point out, can only be derived historically. Often years or even centuries are needed before we see clearly why one scientific theory is better than another. Viewed from another angle, one can only judge the past by the present or by a lessor past. Only those scientific theories which repeat past successes can be judged by criteria developed historically. Since one does not know ln advance what criteria a theory that has not been discovered should be judged on, then it is irrational to believe one can set up laws of demarcation. that can be applied to them.In fact, such criteria inevitably conflict with new and original thought.