But the forces operating in the world of mind, as well as in society, must also be understood, in order to estimate the influence of unbelief in France. In a previous lecture we have seen that in the middle of the seventeenth century the philosophy of Descartes had created a complete revolution in modes of thought. It was only in the philosophy of Spinoza that it produced theological unbelief; but by its indirect influence it had led generally to an entire reconsideration of the first data of reasoning, and the method of establishing truth; and thus had stimulated the struggle of reason against faith, of inquiry against credulity, of progress against reaction, and of hopefulness in the future against reverence for the past. The activity of mind displayed in the literature of the reign of Louis XIV is its first expression.(501) But thoughts ferment long in society before they fully express themselves in form: they first exist as suggestions; then they become doubts; lastly, they pass into disbelief. It was not until the time of the regency,(502) which ensued after the death of Louis, that the literature became impressed with a thoroughly new tone.(503) Other causes of a more direct kind cooperated. The English philosophy of Locke, which marked an epoch in speculation, was introduced at that time. This philosophy however could not have resulted in those speculations which arose in France, if it had not been carried farther by the analysis which Condillac employed in that country, analogous to that of Hume in Scotland. In itself it expressed the reasoning type of mind and thought which reigned throughout the English literature; but the corollaries from it which produced harm were no part of the original system.(504) Condillac, desiring to carry out the analysis of the origin of knowledge, lost sight of the intellectual element in Locke’s account of the process of reflection; denied the existence of innate faculties as well as innate ideas; and attempted to show that man’s mind is so passive, so dependent on the evidence of the senses for the material of its thoughts, and on language for the power to combine them, that its very faculties are transformed sensations.(505) From these premises it was not hard for his followers to draw the inferences of materialism(506) in philosophy, selfishness in morals, and an entire denial of those religious truths which cannot be proved by sensuous evidence. This philosophy began to leaven the mind of France, and was accepted by nearly the whole of French unbelievers.