Over the course of Credport (which is nearly a year now), I have made some very invaulable experiences in terms of disagreeing with your partner that I'd like to share for people who may be in the similar situation.
Everyone is different
First of all, I think it is very important to realize that everyone is different and so are we. Connor and I have been roommates for two years and have likely spent 90% of the last nearly three years together. In fact, we are currently sharing the same bed (talking about Lean Startup right there). In my opinion, we have developed an incredible understanding of each other, despite our large philosophical differences. It is that ability that has allowed us to still have these hour-long discussions about the world without hating each other. In fact this post is a result of one of these discussions.
You will disagree
There is no way around it, you will be arguing. There are so many decisions to be made, especially at a startup, an early-stage company whose purpose (or scalable business model in lean speak) has yet to be found. Everyone wants to know everything, everyone wants to be right. I mean really, who doesn't? We are both very competitive people, we wouldn't be here if we weren't. And I know it sounds conceited, but we also have a history of being right.
You will have to admit that you can be wrong
And that's the hardest thing. In order for you to respect (and retreat to) someone else's opinion you disagree with, you have to de-facto believe (or accept) that you are not right. You will have to admit to yourself that you could be wrong. It seems very obvious now, but it's a lesson that cannot be learned unless you have been through this yourself.
Sure, there are plenty of cases, where in hindsight one of your decisions prove to be wrong, but when it involves another party, the whole game changes. Your decisions are not anymore only affecting you, and nor are you the solely responsible for your fate.
Or to say it blunt: You share responsibility for each other. You are in this together. You are in the same bed (in our case literally).
What it takes
I'm not gonna lie, this has been a new situation for me. Credport is the first company I have co-founded and actually the first complex project I have been doing not solely by myself. In the past I have been modestly successful with being on my own and do my own thing.
That being said, having a joint venture requires you to fully trust your partner. You have to realize that you both share the same goal, you both want your company to succeed. You have to realize that disagreement is not personal. Some people are naturally good at it, some aren't. I admit that it has not been my strong suit. As said, I like to be right. This ability has to be learned, trained and continuously improved.
Now even with the best intentions and behaviors, its not always puppies and kittens. There will be critical decisions to be made on which you disagree. One way we reduce a lot of friction and avoid unnecessary long discussions, is to resort to our responsibility areas. If it's a question about business, Connor has the last word, if it's a product question, I do. It always has to be clear who gets to call the shots in case of disagreement.
Why all this?
It maybe sounds obvious, but I wouldn't be in this awesome situation if it weren't for Connor. Endeavors like these can simply not be done along. Plus it's one hell of a lot more exciting and fun to have a wingman.
Also, if you read this again, you'll see that this could have been perfectly written for relationship counseling, because running a business is a lot like a marriage. Hell, even the US congress could learn a lesson or two when it comes to respectfully disagreeing, do we really need to think that the other party wants deliberately destroy America?