"Science, down to the present day, remains permeated with Malthus's teachings. Political economy continues to base its reasoning upon a tacit admission of the impossibility of rapidly increasing the productive powers of a nation, and of thus giving satisfaction to all wants. This postulate stands, undiscussed, in the background of whatever political economy, classical or socialist, has to say about exchange-value, wages, sale of labour force, rent, exchange and consumption. Political economy never rises above the hypothesis of a limited and insufficient supply of the necessities of life; it takes it for granted. And all theories connected with political economy retain the same erroneous principle. Nearly all socialists too, admit the postulate. Nay, even in biology (so deeply interwoven now with sociology) we have recently seen the theory of variability of species borrowing a quite unexpected support from its having been connected by Darwin and Wallace with Malthus's fundamental idea, that the natural resources must inevitably fail to supply the means of existence for the rapidly multiplying animals and plants."