The Family Guy Fan Theory That Explains Why Brian Is Able To Talk
There are a lot of things about "Family Guy" that don't make sense. Why isn't Peter Griffin in prison for all the various crimes he's committed? Why is everyone so mean to Meg? And how can Brian, a dog, talk when other dogs in this world are just regular animals? The answer to all of these questions is that it's a cartoon, so stop thinking so hard about it.
But some fans aren't content with that, so they've come up with various fan theories to explain details that wouldn't fly elsewhere. One pivotal topic of discussion comes down to why Brian essentially functions as a human being in the show. He's clearly the most intelligent one in the Griffin family, and he's able to date insanely attractive human women, which raises further questions, but let's not get into that right now.
Brian is definitely an outlier within the show's cavalcade of characters, and there's a prevalent fan theory that suggests Brian's actually the writer of all of "Family Guy." He's the one in control, so he tells stories and exaggerates characters as he sees fit. Let's break this theory down.
Brian and Seth MacFarlane are one and the same
Redditor u/raaaaaaaalphie posited the theory years ago, suggesting Brian is the writer of the fictitious world of Quahog. The first piece of evidence is that Brian holds many of the same political and religious beliefs as "Family Guy" creator Seth MacFarlane. MacFarlane also provides the voice of Brian and barely changes his regular speaking voice in the process. The writers of the show could've taken this idea a step further by making Brian the de facto writer of this universe. His writing is often a source of jokes in the show, but Brian could actually be the one depicting everything that happens to the Griffins to the audience.
The Redditor elaborates, "In [Brian's] eyes, everyone in the Griffin family has exaggerated flaws. The only person in the Griffin family that has any reason to hate Meg is Brian which would explain why everyone in the show is so mean to her. Since Peter is an idiot in Brian's eyes, his writings are going to exaggerate it. Same thing applies to Chris." The part about Brian hating Meg actually makes sense in the context of Season 5's "Barely Legal," where Brian accidentally kisses Meg, making her obsessed with him. She makes him eat pie that has pieces of her hair in it, so it's understandable Brian would then show everyone else in the family hating her as much as he does going forward.
It also explains why people don't freak out at the sight of a talking dog. It's from his perspective, so he'll do whatever he thinks is best for the expediency of the story. Will this theory ever be made canon? It's unlikely, but it's fun to view the show occasionally through this lens to see what it changes.