The Importance of Knowledge in Decision Making

There's an epistemological argument for Hayek that you can't know enough about the economy to do anything else and have it work out the way you intend. And yet, if you're going to say that these decisions are based on more knowledge, then the implicit claim is that the kind of knowledge that the market is using is what is relevant for making decisions. So there is a kind of implicit claim here that individual preferences can be aggregated in some way which will give you the outcome that is defensible or at least rejectable.