When handled correctly, arguments can be a good thing (like the Wright brothers famously did). Both parties have the opportunity to learn a lot if it’s done in a healthy way.
If you’re having healthy arguments in good faith, you should lose around half the time. Seth Godin shared about this in a recent post, saying:
If you’re regularly having arguments with well-informed people of goodwill, you will probably ‘lose’ half of them–changing your mind based on what you’ve learned. If you’re not changing your mind, it’s likely you’re not actually having an argument (or you’re hanging out with the wrong people.) While it can be fun to change someone else’s position, it’s also a gift to learn enough to change ours.
More directly, he says that if you’re not willing to potentially lose an argument then you’re simply acting like a toddler. That’s not a good place to be.
Always fight hard for what you believe, for sure, but be willing to change your mind if the facts support a different view.