Duehring into a realm in which I can at the very most only claim to be a dilettante. On such occasions I have for the most part limited myself to placing the plain incontrovertible facts in contrast with the false or crooked assertions of my opponent, as in relation to jurisprudence and many instances with regard to natural science. In other places he indulges in universal views on the subject of natural science theories and therefore on a field where the professional naturalist must range out of his own particular specialty to neighboring regions, where he, according to Herr Virchow's confessions is just as good a "half-knower" as the rest of us. For slight deficiencies and unavoidable errors in the publication I hope that the same indulgence will be extended to me as has been shown the other side of the controversy.
Just as I was completing this preface I received the publishers' notice of a new important book by Herr Duehring. "New Foundations for rational Physics and Chemistry." Although I am very well aware of my deficiencies in physics and chemistry I still believe that I know my Duehring well enough, without having read the book, to venture to say that the laws of physics and chemistry there set forth are worthy of being placed alongside of Herr Duehring's former discoveries and the laws of economics, scheme of the universe, etc., examined in my writings and proved to be misunderstood or commonplace, and that the rhigometer, an instrument constructed by Herr Duehring for measuring temperature will be found to serve not only as a measure for high or low temperature but of the ignorance and arrogance of Herr Duehring. London, 11 June, 1878.
