The broad features of the speculative revolution of which the Encyclopaedia was the outcome, lie on the surface of its pages and cannot be mistaken. The transition from Descartes to Newton meant the definite substitution of observation for hypothesis. The exaltation of Bacon meant the advance from supernatural explanations to explanations from experience. The acceptance and development of the Lockian psychology meant the reference of our ideas to bodily sensations, and led men by what they thought a tolerably direct path to the identification of mind with functions of matter. We need not here discuss the philosophical truth or adequateness of these ways of considering the origin and nature of knowledge, or the composition of human character. All that now concerns us is to mark their tendency. That tendency clearly is to expel Magic as the decisive influence among us, in favour of ordered relations of cause and effect, only to be discovered by intelligent search. The universe began to be more directly conceived as a group of phenomena that are capable of rational and connected explanation. Then, the wider the area of law, the greater is man's consciousness of his power of controlling forces, and securing the results that he desires. Objective interests and their conditions acquire an increasing preponderance in his mind. On the other hand, as the limits of science expand, so do the limits of nescience become more definite. The more we know of the universal order, the more are we persuaded, however gradually and insensibly, that certain matters which men believed themselves to know outside of this phenomenal order, are in truth inaccessible by those instruments of experience and observation to which we are indebted for other knowledge. Hence, a natural inclination to devote our faculty to the forces within our control, and to withdraw it from vain industry about forces--if they be forces--which are beyond our control and beyond our apprehension. Thus man becomes the centre of the world to himself, nature his servant and minister, human society the field of his interests and his exertions. The sensational psychology, again, whether scientifically defensible or not, clearly tends to heighten our idea of the power of education and institutions upon character. The more vividly we realise the share of external impressions in making men what they are, the more ready we shall be to concern ourselves with external conditions and their improvement. The introduction of the positive spirit into the observation of the facts of society was not to be expected until the Cartesian philosophy, with its reliance on inexplicable intuitions and its exaggeration of the method of hypothesis, had been laid aside.