Egan, Kieran (1997). The Educated Mind. University of Chicago Press. стр. 115–116. ISBN978-0-226-19036-5. „Positivism is marked by the final recognition that science provides the only valid form of knowledge and that facts are the only possible objects of knowledge; philosophy is thus recognized as essentially no different from science [...] Ethics, politics, social interactions, and all other forms of human life about which knowledge was possible would eventually be drawn into the orbit of science [...] The positivists' program for mapping the inexorable and immutable laws of matter and society seemed to allow no greater role for the contribution of poets than had Plato. [...] What Plato represented as the quarrel between philosophy and poetry is resuscitated in the "two cultures" quarrel of more recent times between the humanities and the sciences.”
Wallace, Edwin R. and Gach, John (2008) History of Psychiatry and Medical Psychology: With an Epilogue on Psychiatry and the Mind-Body Relation.p. 14Архивирано 16 мај 2016 на сајту Wayback Machine
Wallace, Edwin R. and Gach, John (2008) History of Psychiatry and Medical Psychology: With an Epilogue on Psychiatry and the Mind-Body Relation.p. 14Архивирано 16 мај 2016 на сајту Wayback Machine