I am willing to stamp with my blood to guarantee that the world is material.

-------Feuerbach

People must first eat, drink, live, and clothe, and then they can engage in politics, science, art, religion, etc.

----------Engels

Only in the real world and using real means can real liberation be achieved. There are no steam engines and spindle spinning machines. Slavery cannot be eliminated. Serfdom cannot be eliminated without improved agriculture. When people cannot fully guarantee the quality and quantity of their food, drink, shelter, and clothing, people cannot achieve liberation at all. "Liberation" is a historical activity, not an idea. The "liberation" of activities is caused by historical relationships, industrial conditions, commercial conditions, agricultural conditions, and communication conditions

----------Marx