 He believed that competition and conflict would increase and that war between the imperialist powers would continue until they were overthrown by proletariat revolution and socialism established.He spent much of this time reading the works of Georg Wilhelm Friedrich Hegel, Ludwig Feuerbach, and Aristotle, all of whom had been key influences on Marx.This changed Lenin's interpretation of Marxism; whereas he once believed that policies could be developed based on predetermined scientific principles, he concluded that the only test of whether a policy was correct was its practice.