Love is felt so intensely, it seems inconceivable that it will not always produce a response. Love is antiphonal. The words ‘I love you’ contain an implicit demand. They are incomplete without the answer: ‘I love you too.’ Implicit faith in romantic idealism makes us confident that if we proclaim our love loud enough, we will get an answer. As when calling across a valley, we assume that an echo will acknowledge our effort. But love does not obey physical laws. Sometimes we proclaim our love and there is no reply. Our words are killed by the dead acoustic of a cold heart and the ensuing silence is terrible.

Frank Tallis, Love Sick: Love as a Mental Illness, London, 2004, p. 244