The title says it all really: What was the inspiration and/or origin for Spock's name? The only other Spock I know of is, of course, Dr Spock who wrote about children - was this at all an influence?
Roddenberry sought an alien-sounding name when he created "Spock", and did not know until later of Dr. Benjamin Spock, the pediatrician and author.
Dr. Spock's book Baby and Child Care was published in 1946 and quickly became a huge bestseller, making him a household name in the US and beyond. Roddenberry's two daughters were born in 1948 and 1953, so it seems likely that he would have heard of the real Spock. It's not a very common name, so surely not coincidence. With this in mind, my conclusion is: