The rule against split infinitives was another gem of the prescriptive school of grammar. The CGEL states that there was/is "no rational basis for the prescriptive rule". Again, as with so many other PG rules, "
![No [N]](/emoticons/emotion-45.gif)
o reason was ever given as to why the construction was supposedly objectionable ...". They even got the name wrong; "It should be noted that the term 'split infinitive' is a misnomer".
"Prescriptive rules and recommendations are often motivated by the wish to achieve clarity of expression, in particular to avoid ambiguity. ... A curious feature of the 'split infinitive' rule, however, is that it has the potential to reduce clarity, to create ambiguity." [CGEL]