Thus, without further treatment, it must be obvious that it is impossible for us to over-estimate the importance of Language as the handmaid of Thought. “A sign,” as Sir William Hamilton says, “is necessary to give stability to our intellectual progress—to establish each step in our advance as a new starting-point for our advance to another beyond.... Words are the fortresses of thought. They enable us to make every intellectual conquest the basis of operations for others still beyond.” Moreover, thought and language act and react upon one another; so that, to adopt a happy metaphor from Professor Max Müller, the growth of thought and language is coral-like. Each shell is the product of life, but becomes in turn the support of new life. In the same manner each word is the product of thought, but becomes in turn a new support for the growth of thought. It seems needless to say more in order to show the immense importance of sign-making to the development of ideation—the fact being one of universal recognition by writers of every school. I will, therefore, now pass on to the theme of the present chapter, which is that of tracing in further detail the _logic_ of this faculty, or the _method_ of its development. * * * * * From what I have already said, it may have been gathered that the simplest concepts are merely the names of recepts; while concepts of a higher order are the names of other concepts. Just as recepts may be either memories of particular percepts, or the results of many percepts (_i.e._ sundry other recepts) grouped as a class; so concepts may be either names of particular recepts, or the results of many named recepts (_i.e._ sundry other concepts) grouped as a class. The word “red,” for example, is my name for a particular recept; but the word “colour” is my name for a whole group of named recepts. And similarly with words signifying objects, states, and actions. Hence, we may broadly distinguish between concepts as of two orders—namely, those which have to do with recepts, and those which have to do with other concepts. For a concept is a concept even though it be nothing more than a named recept; and it is still a concept, even though it stands for the highest generalization of thought. I will make this distinction yet more clear by means of better illustrations.