Provided you have a system that works perfectly and consistently ALL THE TIME. But most agree there is no such thing. There are too many variables. Again, take the car example. Why don't we have auto-pilot cars? Do you drive the same way down the same road on a nice summer day, during a foul thunder storm and in icy, snowy conditions late at night? Is there an auto-pilot vehicle that could? What/who is responsibe for the safe conclusion of the journey each time? You, the driver (provided you approach each condition with the same discipline and consistency - i.e. not being overtired, drunk, blindfolded, etc). That said, again, who is responsible for any mistakes? The car?
But that's just my opinion. You started the thread. What is your answer?
I really believe that if you have something that really works, your psychology will be fine enough not to screw it up.
Being disciplined to follow the rules of a winning system is the easy part.
The hardest part of trading is finding a system that works.
Finding a profitable system is just like panning for gold.
And this is the game.