如果我们选择了最能为人类而工作的职业，那么，重担就不能把我们压倒，因为这是为大家作出的牺牲；那时我们所享受的就不是可怜的、有限的、自私的乐趣，我们的幸福将属于千百万人，我们的事业将悄然无声地存在下去，但是它会永远发挥作用，而面对我们的骨灰，高尚的人们将洒下热泪。 

    哲学家们只是用不同的方式解释世界，问题在于改变世界。 

    批判的武器当然不能代替武器的批判，物质力量只能用物质力量来摧毁；但是理论一经掌握群众，也会变成物质力量。

    全部社会生活在本质上是实践的。 在科学上没有平坦的大道，只有不畏劳苦沿着陡峭山路攀登的人，才有希望达到光辉的顶点。

      If we have chosen the position in life in which we can most of all work for mankind, no burdens can bow us down, because they are sacrifices for the benefit of all; then we shall experience no petty, limited, selfish joy, but our happiness will belong to millions, our deeds will live on quietly but perpetually at work, and over our ashes will be shed the hot tears of noble people. The philosophers have only interpreted the world, in various ways: the point, however, is to change it. The weapon of criticism cannot, of course, replace criticism of the weapon, material force must be overthrown by material force; but theory also becomes a material force as soon as it has gripped the masses. All social life is essentially practical. There is no royal road to science, and only those who do not dread the fatiguing climb of its steep paths have a chance of gaining its luminous summits.