I don't agree that ability is simply a matter of innate gifts and therefore unearned. To be sure, many have talents in differing amounts. I was born with certain gifts, an ability to distinguish color variations that tested off the charts, along with an understanding of spatial relationships that also tested off the charts. The former certainly had a role in my pursuing a career in the visual arts. I could distinguish variations in color that others quite simply cannot see. More usefully, I can use color and lighting to help tell the story that I'm working on far better than the average bear, and understand and predict what kind of emotional response the color and lighting choices will evoke in the viewer. The latter allowed me to pack the cargo area of a truck or the trunk of a car very efficiently since I could instantly visualize how the varied shapes of the cargo could most efficiently fit together. The other use was blitzing geometry classes, while turning out proofs in a variety of ways for my amusement though the instructors would occasionally get cross. UCLA did offer me a full scholarship to switch from art to math, but I liked the arts more.Ability is innate. Talents, intellect, other genetic traits.
You cannot raise your IQ. You can damage it, but you cannot raise it.
That is ability.
Great question as always. The answer: by ability.
But whatever the talents I was born with, I worked damned hard to develop those gifts, which in turn extended my ability to make fuller use of my abilities.