 But in fact, he subbed it out for a technical reason. Property was considered an alienable natural right, and the pursuit of happiness was unalienable. But this idea of the pursuit of happiness as the pursuit of virtue, which the founders talked about constantly, and the sources that they drew on talk about constantly, and they include not only those philosophers, but legal writers like Blackstone, or religious writers like Wollaston, and other names we haven't heard of,