(The eminent historian Christopher H. Dawson's explanation of humanisn adds further light to Maritain's view in the previous post.)
"THE Renaissance has its beginnings in the self-discovery, the self-realization and self-exaltation of Man. Medieval man had attempted to base his life on the supernatural. His ideal of knowledge was not the adventurous quest of the human mind exploring its own kingdom; it was an intuition of the eternal verities which is itself an emanation from the Divine Intellect─irradiatio et participatio primae lucis. The men of the Renaissance, on the other hand, turned away from the eternal and the absolute to the world of nature and human experience. They rejected their dependence on the supernatural, and vindicated their independence and supremacy in the temporal order. But thereby they were gradually led by an internal process of logic to criticize the principles of their own knowledge and to lose confidence in their own freedom. The self-affirmation of man gradually led to the denial of the spiritual foundations of his freedom and knowledge. This tendency shows itself in every department of modern thought. In philosophy, it leads from the dogmatic rationalism of Descartes and the dogmatic empiricism of Locke to the radical skepticism of Hume and the subjectivism of later German thought. Reason is gradually stripped of its prerogatives until nothing is left to it but the bare "as if" of Vaihinger."
~Christopher H. Dawson: Christianity and the New Age, Chap. I ─ Humanism and the New Order. (1931)
"THE Renaissance has its beginnings in the self-discovery, the self-realization and self-exaltation of Man. Medieval man had attempted to base his life on the supernatural. His ideal of knowledge was not the adventurous quest of the human mind exploring its own kingdom; it was an intuition of the eternal verities which is itself an emanation from the Divine Intellect─irradiatio et participatio primae lucis. The men of the Renaissance, on the other hand, turned away from the eternal and the absolute to the world of nature and human experience. They rejected their dependence on the supernatural, and vindicated their independence and supremacy in the temporal order. But thereby they were gradually led by an internal process of logic to criticize the principles of their own knowledge and to lose confidence in their own freedom. The self-affirmation of man gradually led to the denial of the spiritual foundations of his freedom and knowledge. This tendency shows itself in every department of modern thought. In philosophy, it leads from the dogmatic rationalism of Descartes and the dogmatic empiricism of Locke to the radical skepticism of Hume and the subjectivism of later German thought. Reason is gradually stripped of its prerogatives until nothing is left to it but the bare "as if" of Vaihinger."
~Christopher H. Dawson: Christianity and the New Age, Chap. I ─ Humanism and the New Order. (1931)