Split infinitives are not ordinarily major threats to clarity, but careful writers avoid them when they conveniently can. "To boldly go where no one has gone before" is just as clear as "boldly to go" or "to go boldly," but split infinitives are likely to draw criticism from some readers. If you want such readers to attend to what you say and not to the placement of adverbs in your sentences, keep "to" and the verb together.
Copyright 1996 Yale University. Revised on Monday, May 20, 1996