The difference is Calvinism requires regeneration and Arminianism prevenient grace. These two however are not the only possibilitiesDepravity is the referenced reason for inability. As we grow in knowledge and understanding our inabilities vanish. Knowledge enables. Depravity is used in both Arminianism and Calvinism to establish a lack of innate ability absent Grace when God has Graciously enabled man to innately reason and grow in knowledge. Thusly there is no difference in any mans abilities absent any physical disabilities to learn.
Both of the positions are fundamentally wrong in how they teach the innate qualities of a human descendent of Adam.