I do not feel like you convince somebody to be a cofounder, they convince you they must be one. If you're talking him into it and it turns out he just doesn't

I do not feel like you convince somebody to be a cofounder, they convince you they must be one. If you're talking him into it and it turns out he just doesn't have the capacity or passion for it which you'd like him to have, you're in for a huge disappointment. Look at it another way—you're trying to seal a larger commitment on paper so you're buying into risk without getting anything tangible back on that investment compared to investing in him as employee #1. Fallout from a bad first employee will never be as bad as fallout from a cofounder you want to remove.