“The ruling ideas of each age have ever been the ideas of its ruling class.” — Karl Marx

The development of civilization and industry in general has always shown itself so active in the destruction of forests that everything that has been done for their conservation and production is completely insignificant in comparison.

The ideas of the ruling class are in every epoch the ruling ideas, i.e., the class which is the ruling material force of society, is at the same time its ruling intellectual force.

Greek philosophy seems to have met with something with which a good tragedy is not supposed to meet, namely, a dull ending.

Without doubt, machinery has greatly increased the number of well-to-do idlers.