"I passionately believe that's it's not just what you say that counts, it's also how you say it - that the success of your argument critically depends on your manner of presenting it"

In this quote, Alain de Botton emphasizes the importance of not just the content of our words, but also the way in which we deliver them. He believes that the success of our arguments is greatly influenced by our manner of discussion. This suggests that the tone, body movement, and total delivery of our message can significantly impact how it is received by others. De Botton's usage of the word "passionately" highlights the intensity of his belief in this idea. It serves as a suggestion to carefully think about not simply what we state, however also how we state it, in order to successfully convey our message and persuade others.