The special part played in the society by Huxley was to show that many of the axioms of current speculation are far from being axiomatic, and that dogmatic assertion on some of the cardinal points of metaphysic is unwarranted by the evidence of fact. To find these seeming axioms set aside as unproven, was, it appears from his "Life," disconcerting to such members of the society as Cardinal Manning, whose arguments depended on the unquestioned acceptance of them. It was no doubt the observation of a similar attitude of mind in Mr. Gladstone towards metaphysical problems which provoked Huxley to reply, when asked whether Mr. Gladstone was an expert metaphysician--"An expert in metaphysics? He does not know the meaning of the word." In addition to his share in the discussions, Huxley contributed three papers to the society. The first, read November 17, 1869, was on "The views of Hume, Kant, and Whately on the logical basis of the doctrine of the Immortality of the Soul," showing that these thinkers agreed in holding that no such basis is given by reasoning, a part, for instance, from revelation. A summary of the argument appears in the essay on Hume ("Collected Essays" 6 201 sq.) On November 8, 1870, he read a paper, "Has a Frog a Soul? and if so, of what Nature is that Soul?" Experiment shows that a frog deprived of consciousness and volition by the removal of the front part of its brain, will, under the action of various stimuli, perform many acts which can only be called purposive, such as moving to recover its balance when the board on which it stands is inclined, or scratching where it is made uncomfortable, or croaking when pressed in a particular spot. If its spinal cord be severed, the lower limbs, disconnected from the brain, will also perform actions of this kind. The question arises, Is the frog entirely a soulless automaton, performing all its actions directly in response to external stimuli, only more perfectly and with more delicate adjustment when its brain remains intact, or is its soul distributed along its spinal marrow, so that it can be divided into two parts independent of one another? The professed metaphysician might perhaps tend to regard such consideration as irrelevant; but if the starting-point of metaphysics is to be found in psychology, psychology itself depends to no small extent upon physiology. This question, however, Huxley did not pretend to solve. In the existing state of knowledge he believed it to be insoluble. But he thought it was not without its bearing upon the supposed relations of soul and body in the human subject, and should serve to give pause to current theories on the matter.