“Conduct and character are largely determined by the nature of the words we currently use to discuss ourselves and the world around us.”

Quoted as the opening passage of "BOOK ONE: The Functions of Language" in Language in Thought and Action (1949) by S. I. Hayakawa, p. 3
Words and Their Meanings (1940)
Context: A great deal of attention has been paid … to the technical languages in which men of science do their specialized thinking … But the colloquial usages of everyday speech, the literary and philosophical dialects in which men do their thinking about the problems of morals, politics, religion and psychology — these have been strangely neglected. We talk about "mere matters of words" in a tone which implies that we regard words as things beneath the notice of a serious-minded person.
This is a most unfortunate attitude. For the fact is that words play an enormous part in our lives and are therefore deserving of the closest study. The old idea that words possess magical powers is false; but its falsity is the distortion of a very important truth. Words do have a magical effect — but not in the way that magicians supposed, and not on the objects they were trying to influence. Words are magical in the way they affect the minds of those who use them. "A mere matter of words," we say contemptuously, forgetting that words have power to mould men's thinking, to canalize their feeling, to direct their willing and acting. Conduct and character are largely determined by the nature of the words we currently use to discuss ourselves and the world around us.