If love is love, it's free
This is said by Dr. Tamkin to Tommy when Tommy claims his love for Olive to have nothing to do with money (Chapter V). This very small statement is quite full of meaning, which points to the most redeeming elements that exist in the novel: love and freedom. Love is the key to freedom. Tommy cannot feel free and become unburdened, for example, until he feels a connection and love for the entire "larger body" of humanity as a whole. He cannot be free until he loves a stranger, the dead man at the funeral in the end. Also, it suggests the fact that his love for Olive is probably "true."
Freedom is mentioned constantly because that is the ultimate goal. In other words, Tommy needs to achieve truth and he needs to recognize his true self, but cannot do that until he is free and vice a versa. Furthermore, it is Dr. Tamkin that is, again, providing him with the path to his destiny. The quote points also the language that Dr. Tamkin is constantly using and which is appealing to an idealist Tommy. It is, after all, the image of Dr. Tamkin that will lead him, in the end to the chapel where he has his final moment of "rebirth."