1, basic stage:
History of Western Philosophy, Sophie's World, History of China's Philosophy, Philosophical Notes, etc.
2. Promotion stage:
Kant's three major criticisms, the original works of Hegel, Feuerbach, Marx, Heidegger, Nietzsche and others. Specific Baidu search.
3. Easy reading after class:
A cultural book introducing various ideas. Chrysanthemums and knives about Japanese culture and so on.