This is the story of Harvey's natural philosophy, how he acquired it, what it was and how while practising it he discovered that the blood circulates around the body. It is also the story of how that discovery and its natural philosophy were met and understood by people with different philosophies and how as a result they accepted or dismissed Harvey's doctrines.

Before Harvey's doctrine changed natural philosophy and medicine as a whole – that is, before it was ‘accepted’ – some sort of consensus had to exist. Unless there was widespread agreement that the blood circulated, it would have remained a minority view, and to most people a false one. Without some kind of consensus the natural philosophy of the time would not have changed (and historians are agreed that it changed so rapidly that it amounted to a revolution in what used to be called ‘science’). This story accordingly includes considerations about mechanisms which contributed to or discouraged the formation of a consensus. Such mechanisms include formal structures of argument and expression, developed and used in the universities and common to most educated men. Such structures had a role in Harvey's natural philosophy before he discovered the circulation, in his announcement of its discovery and in other people's reaction to that discovery.

Another factor that made a consensus possible was the structure and arrangement of groups of people, whether in medical faculties, professional colleges or wider national and religious groups.