too many referees?

[msgreen]

i'm working on applications for a summer position, and need 2 referees for most of the positions i'm applying for. I know I have one great letter lined up, but I was working on getting a second over the holiday break. I asked a professor in my field, who I had a class with last fall, before Christmas. I hadn't heard from him by the end of the winter holidays, so I asked a second professor, who i had a class with in a tangential field but who I know a little better than the first professor that I asked. She promptly responded and was happy to write me a letter, which was great until I heard back from the first professor. He told me he would be willing to write me a letter, but requested a meeting before he started working on it and mentioned that he will also be writing letters for other students he knows better so he will be relatively busy.

I think I'm more confident in the letter the professor who responded a few days ago will write for me, but how do I tell the professor who just responded I no longer need the letter I asked him for? I don't want to impose unnecessary work, but I also don't want it to seem like I don't value his willingness to get to know me and write me a letter. Should I use his letter for the few positions that say they accept a third letter?

thanks!

Edited January 10, 2017 by msgreen

[fuzzylogician]

I'm confused at this point about which one is the "first professor" and which one is the "second professor", so ignoring those labels: If you think the letter you'll get will strengthen your application compared to not having it at all, it stands to reason to add it when possible. Otherwise, assuming that the professor you don't want a letter from anymore is the one who essentially said that he'll be writing stronger letters for other people, you might reply to say thank you and that his reply made you realize that you might be able to find someone else who knows you better and could write a better letter than [original prof], so you'll ask them but you thank [original prof] for his willingness to help. As long as you're polite, I doubt this person should be offended. He's going to be happy not to have to do this extra work, and will appreciate knowing that sooner rather than later.