Even if there are other more challenging aspects between you, this one helps keep you on the same wavelength. You agree on most things, and even the subjects you don't agree on are interesting, because you get to look at both sides of an issue together and debate over it. At base, you think in similar ways -- your thought processes take similar tracks, ones that each of you recognize in the other.
The individual style in which each of you reasons things out and processes information blends together nicely, so you share a feeling of familiarity. Conversation flows; your ideas come out in a tumbling rush, and you egg each other on, urging each other for more. Both intellectually and philosophically, you're on a par. You love discussing things together, both to form your own thoughts as well as to get the other's take on it. You don't shy away from profound subjects, either; they have as much appeal as lighter ones. You probably share interests in many subjects, and want to take classes together or at least go see films or lectures and discuss what you learned afterward. Whatever differences there may be between you are greatly mitigated by this influence, which acts as a bridge between you.