What are humans limited by? We are limited by time and by space.
We are limited in time because we are mortal beings, bound to the past by our birth and to the future by our death, delimiting the short interval of our lifetimes.
We are limited in space because we are finite beings. At each point of time we are constrained by what we are and what we might become. We are bound both by our actuality and our possibility. Our nature defines our actuality and our nurture sets our possibility.
Certainly, we can transcend our limitations, but this just means they weren’t really the true limits after all. We can’t say for certain what our real limits are, so that’s a good thing.
This fourfold also reminds me of the following modal square of opposition. At birth, much is possible. At death, all becomes impossible. Nurture is contingent and Nature is necessary.