#but uh - yes. doc's an exceptional mentor and i'll defend this to my last breath

[doctorbrown]

Do you think Doc is a good mentor? Why or why not?

There's not a shadow of a doubt in my mind when I say yes, Doc is a good mentor. A great mentor, actually.

It's easy to cast him aside because Doc's extremely eccentric and most people, if they're not afraid of him/extremely wary of him, they think he's out of his mind because he's not afraid to push boundaries and challenge everything around him, but Doc is practically meant to be a mentor. He slotted so perfectly into the role without even realising it when Marty came along and it just kind of continued from there, spilling over with Jen, his own kids/family, and even (eventually) Marty & Jen's kids.

Before I even get into my ramblings/explanations, all we really need to do is look at his relationship with Marty to see that. While Marty may be the main protagonist/focus across all three films, every change and good thing that subsequently happens with the new Lone Pine timeline is indirectly because of Doc and the mentorship/guidance he's given to Marty since the day they met.

Some examples we see of Doc's mentorship/friendship and the impact it has upon Marty:

He has not only built up Marty's confidence and self-esteem, but encouraged him to always pursue his dreams. You can accomplish anything if you put your mind to it. That very advice changes the course of George & Lorraine's lives entirely. And Doc himself is living proof of that. It's not just something he tells the kid. Hell, even Jen says in pt1, 'It's like Doc's always saying—'

Doc has never treated Marty like he was stupid, unintelligent, or just some kid who wouldn't understand. There are always multiple ways of tackling a problem and Doc shows him this when he finds other ways to explain the scientific/technical parts of whatever he's working on, because he knows Marty enjoys hearing about it and being included.

He may have kept the time machine project a secret from Marty for a few years, but as a true mentor does, once the time comes for temporal experiment number one, he's not only inviting Marty along, but eagerly explaining exactly how the machine works.

Doc is incredibly attentive and this makes him a very good mentor, especially with Marty. Even at the beginning of pt1, before we have any idea who Doc is, we learn that Doc knows Marty enough to ring his own home with the idea that he'd be there to pick up the phone.

Encouraged him to pursue his music dreams, instilling in him the belief that he doesn't have to pursue a career as a teacher or a scientist or a lawyer just because it's what everyone else does. Doc goes so far as to purchase/keep a guitar in the garage specifically for Marty. Doc doesn't play.

Given him the chance to get advice from somebody attentive who wasn't his parent and wouldn't treat him as such. Doc has such a wealth of life experience and advice to offer and everything can be a teaching moment.

Gave him the tools to make a difference in his own life, and we see this especially at the end of pt3, when Marty finally learns how to not fall victim to being goaded/peer pressured into losing his temper by being called a chicken.

And now that I've gotten some of those out of the way, I'm going to keep rambling.

Another thing that makes Doc a good mentor is that Doc is not a one size fits all kind of guy in his approach to things. He tailors everything to best tackle the problem at hand, and this extends to people, too. The way he teaches Jules something won't be the way he teaches Verne something, or Marty something. A good mentor understands the person they're working with, I think, and knows the best ways to impart their wisdom and knowledge on them and Doc is exceptional at this.

But another thing that makes Doc a good mentor is that he typically doesn't hold things back, and this is something I think makes all the difference when trying to teach someone. There's a fine line that has to walk and sometimes, criticism and harsh reality is part of that.

Doc's rather open and honest with those around him (he doesn't sugarcoat harsh truths/realities and even in the deleted/scrapped scene back in '55 when Marty asks him how long he'd have if getting his parents together at the dance didn't pan out, Doc straight up admits that he has no idea. And sure, you can argue that well, that's '55 Doc and he didn't really know Marty then, but he does that throughout the films enough that my point still stands.)

One could try and make the argument that he's reckless and therefore not fit to be a mentor to anyone younger than him (or at all I guess) but at every turn, we always see Doc being the first one to stick his neck out and try to protect others. Granted, there are circumstances/situations that were simply unavoidable (Marty can't repair the time machine for example, so he had to go off and deal with Biff, etc) but for the most part, when the chance was there, this holds:

A second lab for the nuclear/more dangerous experiments. Run for it, Marty! I'll draw their fire! (Also the fact that Doc's genuinely surprised that they found him implies that he attempted to take some measure of precaution in his dealings with them to get the plutonium but, clearly, it wasn't enough.) The entire Clock Tower scene at the end of pt1. The constant reminders about the dangers of being seen in the past. The Delgado mine plan and the emphasised don't come back for me, go home and watch my dog and be safe. There's so much.