Splitting infinitives

I just finished reading a small book on the English language. It’s called "Mother Tongue, The English language and how it got that way". In the section about grammar is poses the point "What is wrong with Splitting infinitives" and then it comes to the conclusion; "I cannot find any particular reason why we cannot split out infinitives".

I was wondering on all of your feeling on this subject.

-Justin

ps, sorry about my spelling/grammar. Its never been my strong point.