I found this book in a trashbin. If nothing else, it's got lots of cool black and white photos, some by Weegie. From page 365:
"We can give the following practical definition of intelligence: Intelligence is that which such an intelligence test measures. The statement sounds empty but isn't, for it implies all the careful steps that have gone into the construction of the tests. The tests constructed by different workers all lead to scores with high intercorrelations; therefore they are measuring something in common. What they measure in common defines intelligence."