I am wondering what level of relationship one needs with a professor to ask for a LOR. I'm a Master's student and I essentially work with 1 professor very closely. I have taken 2 of his classes, he is an adviser to my Master's program, and also serves as my thesis supervisor. He is very supportive and has expressed great confidence in me, so I am very excited about him providing a letter for me. However, I haven't established this kind of relationship with any other professors at my current university.
I'm an interdisciplinary student (PPE program, but I focus on political philosophy), and unfortunately I had quite a few economics course requirements my first year. I know a letter from an economist would be worthless to a philosophy department, so I haven't even bothered with those professors, although I am friendly with some. There is one interdisciplinary philosophy professor that I have taken one course with who I really admire, though I don't know him. I received an A in the class and will take another class with him this Fall. I am thinking of asking him for a LOR but I'm not sure if that would be strange.
The final professor is someone I actually haven't met yet, but my thesis supervisor has been urging that I have a meeting with him as he is from a great institution and experienced in my topic. I should be meeting with him later this month, and I hope to give him an excerpt of my working thesis to look over later in the fall. I won't ever have had a class with him, but I'm hoping 2-3 meetings with him and a look over my writing as well as raving from his close colleague will allow him to serve as a good writer.
The reason I say all this is because I recently read this from A Splintered Mind:
"If a professor gave you an A (not an A-minus) in an upper-division philosophy course, consider her a candidate to write a letter. You needn't have any special relationship with her, or have visited during office hours, or have taken multiple classes from her -- though all those things can help. Don't be shy about asking, we're used to it!" (http://schwitzsplinters.blogspot.com/2007/09/applying-to-philosophy-phd-programs_20.html)
Am I misinterpreting that I need to be chummy with all of my letter writers, or are others asking for LORs from professors whose classes they simply performed well in, and that's it? I feel I've over stressed myself about this one aspect - I almost considered delaying my application a year in order to manufacture some relationships with professors for more LOR options.
I need more coffee.