“the concepts race and class must not be confused. In studying the history of the development of human society the really existing class struggle must not be replaced by an invented ‘race struggle’. From the above it may be seen that it is typical of racism to confuse the biological category of race with other categories of a social character, such as nation and class. The unprincipled way in which racism identifies race with nation or class depending on whether it is necessary to justify war between nations or exploitation within one nation, shows clearly that racism is unscientific and reactionary.”