No, a thumb is a thumb and a finger is a finger. All can be referred to as digits. Please Register or Log in to view the hidden image!
Yuh, a thumb is a finger (much to the obvious delight of brand new parents s/he has 10 fingers and ten toes!). It's actually called the first finger, next to the overused index finger and in scientific mumbo jumbo is called a 'pollex'. Having only two bones, compareed to its three boned counterparts and being opposable and being able to clasp makes it a truly 'special finger'. Please Register or Log in to view the hidden image!
They just named it thumb, still a finger.Please Register or Log in to view the hidden image! http://en.wikipedia.org/wiki/Index_finger