To this extent they make a web. The size and character of the web will depend on our interests. Someone who likes number theory will discover facts different from those discovered by someone who likes zoology. In her 1987 article Putnam argues that fact and value form a seamless web . In discussing action we need to suppose a web of belief and desire made up of orthogonal strands, but I want to argue that it need not be a seamless one.
Extrinsic values are partly factual, but intrinsic values are independent of facts.
Suppose that health were an intrinsic value. It could be an extrinsic one too, for example in so far as healthy doctors normally can work harder and cure patients better than can unhealthy ones. Many, perhaps most, disagreements about what ought to be done, are disagreements about means to agreed ends, and hence the disagreements are about matters of fact. There need not even be agreement about ultimate ends. If one disputant is a Kantian whose ultimate end is respect for persons and another is a utilitarian whose ultimate end is maximization of happiness, they may agree on seeking how to bring about some intermediate end which promotes both respect for persons and maximization of happiness.