Lastly, the lowest influence of all is that which sometimes regulates what may be termed the commercial side of science. Here the demand is very apt to control the supply. New facts and legitimate conclusions cannot be produced with sufficient rapidity to satisfy the popular craving, or they are not sufficiently exciting to compete with other attractions. Science has then to enter the domain of imagination, and the last new generalization--showy and specious, but perhaps baseless as the plot of the last new novel--brings grist to the mill of the "scientist" and his publisher. Only one permanent and final remedy is possible for these evils, and that is a higher moral tone and more thorough scientific education on the part of the general public. Until this can be secured, true science is sure to be surrounded with a mental haze of vague hypotheses clothed in ill-defined language, and which is mistaken by the multitude for science itself. Yet true science should not be held responsible for this, except in so far as its material is used to constitute the substance of the pseudo-gnosis which surrounds it. Science is in this relation the honest householder whose goods may be taken by thieves and applied to bad uses, or the careful amasser of wealth which may be dissipated by spendthrifts. It may be said that if these statements are true, the ordinary reader is helpless. How can he separate the true from the false? Must he resign himself to the condition of one who either believes on mere authority or refuses to believe anything? or must he adopt the attitude of the Pyrrhonist who thinks that anything may be either true or false? But it is true, nevertheless, that common sense may suffice to deliver us from much of the pseudo-science of our time, and to enable us to understand how little reason there is for the conflicts promoted by mere speculation between science and other departments of legitimate thought and inquiry. In illustrating this, we may in the present lecture consider that form of sceptical philosophy which in our time is the most prevalent, and which has the most specious air of dependence on science. This is the system of Agnosticism combined with evolution of which Mr. Herbert Spencer is the most conspicuous advocate in the English-speaking world. This philosophy deals with two subjects--the cause or origin of the universe and of things therein, and the method of the progress of all from the beginning until now. Spencer sees nothing in the first of these but mere force or energy, nothing in the second but a spontaneous evolution. All beyond these is not only unknown, but unknowable. The theological and philosophical shortcomings of this doctrine have been laid bare by a multitude of critics, and I do not propose to consider it in these relations so much as in relation to science, which has much to say with respect to both force and evolution.