In saying that capital is ‘sufficient’, I mean that there is enough of it to meet our needs. That’s what I set out to show in this part of the book. The only way to do so is by examining what those needs are, and separating them clearly from our unlimited wants. We must then consider population trends, so we can see how many humans are likely to have those needs in the future. Only then can we attempt to see if our existing capital is sufficient to meet them.