It’s an idea he is being critical of but this is beautifully put by Roberto Unger in The Religion of the Future:
Humanity rises. Its rise is not inevitable, not at least in the more guarded and realistic versions of the romance of ascent, but it is possible. (Auguste Comte and Karl Marx, two philosophers of this romance, were not so circumspect.) We the human race, the species, have already gone far to diminish our haplessness before nature. When we depended completely on her, we used to worship her. Now we have built great civilizations. We have formed, through science and technology, instruments with which to extend our powers and to prolong our lives. We have created opportunities for many more people to have much more time to explore the secrets of the universe as well as the workings of society and of the mind. All these achievements are only a beginning. The watchword of the romance of the ascent of humanity is: you have not seen anything yet.