 Consider also, however, the challenges mentioned above to the fundamental tenets of logical empiricism that remain issues of intense discussion: challenges to its conception of the nature of empirical theory and of what is distinctive about the formal sciences. That to this day no agreement has been reached about how its proposals are to be replaced is not something that is unique to logical empiricism as a philosophical movement, but that they remain on the table, as it were, shows the ongoing relevance and centrality of its work for philosophy of science.