They can work as a kind of plunder. Say western man has this urge to plunder the treasures of the east. Feed himself the right idea, and it is possible for his to do so. All the books analysing the decadence of modern ideas. Presumably one could go back a long way.
Decadence is what frustrates one s own projects.
Russell quoted as saying it gives support to Berkeley. This strange hybrid world, part idealist, part materialist. Nietzsche , says Lewis, gives a certificate of blue blood, But Bergson excites through his bestowal of a certificate of reality. Memory is dead, he promotes the idea of the superiority of action, Which people find very exhilarating and exciting. Magical power of ideas in the 20s and 30s.