Once, my mother-in-law, who knows to leave my Japanese knives alone, grabbed an old rusty carbon knife from my block to slice some Chinese eggplant in-hand. For making stuffed eggplant, her technique involves alternating between slicing all of the way through and cutting 90% though the eggplant. She uses her thumb to feel when the knife has reached the proper depth for the 90% cuts. On her first cut she made a 1/4" deep gash in her thumb before she felt the edge touch her thumb. Once she realized that even my old rusty knives were razor sharp (and after cleaning up her thumb) she was able to finish up without further incident.
I'll let you draw your own conclusion.