The origin of this problem is that in the past "wise" was written with long "s". The only difference between old style "f" and long "s" is an extremely narrow

The origin of this problem is that in the past "wise" was written with long "s". The only difference between old style "f" and long "s" is an extremely narrow and short horizontal stroke added to make an "f". That stroke frequently becomes invisible in an aged book, where you can no longer decide which was the original letter.