mental phenomena pertain to certain animals, not to the totality of all organized beings, nor even to all animals; this I maintain without hesitation. We have no reason yet to affirm that the lowest animals possess psychic attributes; these we find only in the higher animals, and with perfect certainty only in the highest." Verily, Haeckel is right when he says that any zoölogist, on reading this sentence, must throw up his hands in astonishment and ask, "Where would Virchow fix the point at which the soul suddenly enters the previously soulless body?"
But Haeckel deals his adversary a still more telling blow when, in the fifth chapter, "Genetic and Dogmatic Method of Teaching," he repudiates Virchow's theses touching the freedom of research and the restriction of the liberty of teaching. Virchow would have only objective knowledge taught in educational institutions. Haeckel, on the whole, only enlarges upon what I said in reply to Virchow eight months ago, when I gave to the Virchovian prescription this form: Give the student just so much as he requires to pass his examination and no more. As Haeckel justly observes regarding Virchow's suggestion that nothing should be taught which is not absolutely certain, all sciences, with the exception of lower mathematics, would have to be stricken from the lecture-list; and, as Helmholtz very properly remarks, it behooves us to declare that the teacher's work can never bear fruit, save inasmuch as it conveys to the student a conception of "how the thoughts of independent thinkers are moving."
The chapter entitled "The Theory of Descent and Social Democracy" is a brief one, because, as Haeckel tells us, the amazing denunciations pronounced by Virchow called forth from the moment of their publication the just indignation of thinking men, and were signally rebuked. It is a pity that Haeckel did not himself conform to the principle which he laid down toward the close of his chapter, where he says: "Wherein does all this concern the scientific investigator? His sole and only problem is this, to ascertain the truth, and to teach what he has recognized as true, without regard to what corollaries the various parties in state and church may draw from it." This was the right reply, nay, the only one, to make to Virchow's ill-judged utterance; but, instead of following it up, Haeckel endeavors to prove that the Darwinian tendency can only be aristocratic. A man can read in the book of Nature whatever he pleases, just as in the Bible; but Darwinism is neither socialistic nor aristocratic, neither republican nor monarchical; it is an explanation of the most diversified natural phenomena, but it rests on one simple principle. Such is Darwinism—nothing more, nothing less.
In the closing chapter, "Ignorabimus et Restringamur," Haeckel criticises Du Bois-Reymond and his speech made in 1872. Of this chapter we have only to say that we fully accept all that the author writes concerning the decline of natural science at the University of Berlin. How far ossification has advanced there, may be understood when we reflect that the chair once filled by Johannes Müller is to-day occupied by
