"Attempts to regard a molecule as consisting of specific atoms or ionic units held together by discrete numbers of bonding
electrons or electron pairs are considered as more or less meaningless."
Robert Mulliken. Selected Papers of Robert S. Mulliken, D.A. Ramsay and J. Hinze, eds., p. 451. 1932.
"The paper of Heitler and London on H2 for the first time seemed to provide a basic understanding, which could be extended to other molecules. Linus Pauling at
the California Institute of Technology in Pasadena soon used the valence bond method. . . . As a master salesman and showman,
Linus persuaded chemists all over the world to think of typical molecular structures in terms of the valence bond method."
Robert Mulliken. Life of a Scientist, pp. 60-61. 1989.
"Pasadena at that time seemed an earthly paradise, with good science too. We had a dip in the Pacific Ocean at Christmas .
Although Pauling and I were at that time rivals on the subject of valence bond theory, we had friendly relations with the
Pauling family: Linus and Ava Helen one day took us for a memorable expedition into the desert."
Robert Mulliken. Life of a Scientist, pg. 97. 1989.