Let met add two quotations:

1. Fermat's motto was "Multi pertransibunt et augebitur scientia" (many will pass 
   through and knowledge will be increased). At another occasion he wrote about 
   "passing the torch to the next generation", which I find particularly nice.

2. "When kings  are building, carters have work to do". Kronecker quoted this, in his 
   letter to Cantor of September 1891.