Shaneice - would he read any books on parenting?
can you start by talking about what you want for your child - e.g he will be confident, know right from wrong, be able to make decisions, be happy etc etc
Then talk about the best way to bring these about...like thinking about his stage of development, thinking about the differences between naughty behaviour and accidents, and the importance - and above all effectiveness of using positive affirmation to encourage good behaviour, and encourage when learning new things.
Tell him that praising positive behaviour has been proven time and time again to be more effective in getting little ones to 'behave' and to get things right when they are learning new things.
That you are not a 'soft touch',because you want the same outcomes as him, BUT you are prepared to use more effective methods to succeed.
can he be the only person in the land who has not watched those parenting programmes which focus on reward?? (and some sitting in naughty spot - but at 2 they still so badly want to get things right, it's easiest to work with that)
I will be honest. the idea of smacking a two year old for missing the potty makes me feel ill. I think people are right to be saying you need to come to an agreed understanding of parenting, but truly, I would chuck out a man who insisted that he would not change his ways if it involved smacking a 2 year-old for missing a potty. It's cruel - and will lead to trouble for your child as he grows.