Any attempt to define the meaning of the abstract words of a language L by words of the same language L results in a system of explanations of empty meaning. Every meaningful language L must be founded on basic words ("prime words") which cannot be explained by words of L. The prime words of our first language (the mother tongue) must be explained by a pre-linguistic procedure. This necessitates the existence of certain innate ideas if the meaning of prime words is demonstrated by gestures, tones of voice, and other physical actions.