According to him, nature is a continuously flowing stream. It uses thought as an instrument or tool to pass from a given situation, full of ambiguities and disharmonies, to a new and better situation. Although this new situation contains elements implied in the former, it is richer and better because of its new meaning and greater complexity. Like James, Dewey maintains that the mind is an instrument for realizing purposes. Ideas are teleological weapons of mind.
Ideas are plastic and adaptable.
They owe their stability to the vital functions which they serve. In other words, the intelligence, profiting from past experiences, adapts them as means to new experiments in order to test their value. Ideas emerge in thought under the stimulus of the difficulties which are found within every situation. These ideas serve as a point of reference for action in a determined direction toward a better situation. Ideas are thus instruments of action.