Moreover, the comprehensive survey of existence which can be taken by a modern man of science is almost sure to be interesting and instructive, when properly interpreted with the necessary restrictions and expansions; and if it be found that the helpful portions are unhappily accompanied by over-confident negations and supercilious denials of facts at present outside the range of orthodox science, these natural blemishes must be discounted and estimated at their proper worth; for it would be foolish to imagine that even a diligent student of Nature has special access to the kind of truths which have been hidden from the nominally "wise and prudent" of all time. So far as Professor Haeckel's writings are read by the thoroughly educated and well-informed, they can do nothing but good. They may not, indeed, convey anything particularly new, but they furnish an interesting study in scientific history and mental development. So far, however, as they are read by unbalanced and uncultured persons, with no sense of proportion and but little critical faculty, they may do harm, unless accompanied by a suitable qualification or antidote, especially an antidote against the bigotry of their somewhat hasty and scornful destructive portions. To the intelligent artisan or other hard-headed reader who considers that Christian faith is undermined, and the whole religious edifice upset, by the scientific philosophy advocated by Professor Haeckel under the name "Monism," I would say, paraphrasing a sentence of Mr Ruskin's in a preface to _Sesame and Lilies_:—Do not think it likely that you hold in your hands a treatise in which the ultimate and final verity of the universe is at length beautifully proclaimed, and in which pure truth has been sifted from the errors of all preceding ages. Do not think it, friend: it is not so. For what is this same "Monism?" Professor Haeckel writes almost as if it were a recent invention, but in truth there have been many versions of it, and in one form or another the idea is quite old, older than Plato, as old as Parmenides. The name "Monism" should apply to any philosophic system which assumes and attempts to formulate the essential simplicity and _oneness_ of all the apparent diversity of sensual impression and consciousness, any system which seeks to exhibit all the complexities of existence, both material and mental—the whole of phenomena, both objective and subjective—as modes of manifestation of one fundamental reality. According to the assumed nature of that reality, different brands of monistic theory exist:— 1. There is the hypothesis that everything is an aspect of some unknown absolute Reality, which itself, in its real nature, is far beyond our apprehension or conception. And within the broad area thus suggested may be grouped such utterly different universe-conceptions as that of Herbert Spencer and that of Spinoza.