Michor, Hardy Littlewood Rules

Hardy Littlewood Rules for Mathematical Collaboration

Godfrey Harold Hardy FRS (7 February 1877 – 1 December 1947) and John Edensor Littlewood FRS (9 June 1885 – 6 September 1977) were mathematician who worked together in Cambridge in the first half of the twentieth century. They had a long and fruitful mathematical collaboration based on the following rules:

Rule 1: It didn't matter whether what they wrote to each other was right or wrong.
Rule 2: There was no obligation to reply, or even to read, any letter one sent to the other.
Rule 3: They should not try to think about the same things.
Rule 4: To avoid any quarrels, all papers would be under joint name, regardless of whether one of them had contributed nothing to the work.

They're all about trust.
Mat Roberts comments on them as follows:
The interesting thing for me about the rules, is that they're all about trust. In any creative work you have to be able to make mistakes; you can't do anything really good if you're fearful. The first rule codifies this "when we work together mistakes are OK, you can trust me not to criticise". The second and third rules say to me "don't feel obliged by our collaboration, I trust you to work on something interesting, so work on it and don't worry about what I'm doing." The final rule cements the trust, "I know you will contribute something useful, so don't worry about it - we publish together no matter what".

Interestingly, in November 1919, Hardy wrote to Bertrand Russell about his work with Littlewood. (Unpublished letter in the Bertrand Russell Archives, Box 5.21, William Ready Division of Archives and Research Collections, McMaster University, Hamilton, Ontario, Canada.)

"I wish you could find some tactful way of stirring up Littlewood to do a little writing. Heaven knows I am conscious of my huge debt to him ... but in our collaboration he will contribute ideas and ideas only ... all the tedious part has to be done by me [or] it simply won't be done ... I can get absolutely no help from him at all; not even an inquiry as to how I am getting on!"

The rules were spelled out in

Bohr Harald (1952): Looking Backward. Collected Mathematical Works. 1. Copenhagen: Dansk Matematisk Forening. xiii–xxxiv