Chapter 1 of Dr. Médaille's book, The Political Economy of Distributism, is now up: Chapter I: What's in a Name?

This is how he explains the failure of the distributivists:

The Failure of the Distributists

Although this book must be a critique of modern economics, it must start with a critique of modern distributists. I say “modern” distributists because distributism itself is nothing more than the rediscovery of an older view of economics. Until the 16^th century, there was no real dispute that economics was a colony of ethics, rooted in the political order and dependent on distributive justice. No philosopher or theologian worthy of the name, beginning with Aristotle, was without his economic commentary. He felt it merely part of his natural function to comment on the real affairs of real men, and the economic and political orders were simply part of that commentary. So very nearly the full weight of human opinion, taken as a whole, comes down on the side of the distributists. While distributism adds to modern economics precisely what it lacks to become to a real science—the science of Political Economy—distributists themselves have often been reluctant to put their case in economic terms. They have often argued from moral terms; they have placed their arguments in the necessary connection between free property and free men; they have argued on agrarian terms, on the natural rhythms of life and social order often disrupted by modern capitalism; they have argued from Catholic teaching and the social encyclicals. But on the whole, they have been unwilling or (I’m afraid) unable to enter the economic debate on purely economic terms.

and

Despite these successes in both theory and practice, however, it is too often the case that in any discussion of economics, the distributist is likely to be the least well-versed in the science; he is, too often, the one least able to place his argument in economic terms, and too ready to retreat to moral arguments. This has unfortunate consequences for distributism as a movement. First, we often fail to convince others of the economic soundness of our case. Second, those distributists who have an interest in economics find insufficient sustenance in distributism, and often drift off to Austrianism or Keynesianism or socialism, things which are nearly the opposite of distributism. Finally, we cannot recognize the similarities between our own positions and allied positions like Mutualism and Georgism. And failing to recognize these similarities, we fail to recognize our natural allies. We even fail to recognize, too often, that which is valid and useful in neoclassical and Keynesian theories. All of this gives distributism a parochial cast. We end up marginalizing our own theory, simply because we often have a marginal understanding of the theory.

But if the distributist will only enter the economic lists, he will find weapons to hand and armor enough to stand against any opponent. Our theory is competitive at the intellectual level and thoroughly demonstrated at the practical level; we fill the gaps in the science of political economy that neoclassical economics, and all its variants, cannot. We do not need to stand on the margins, but in the mainstream.

What are characteristics of modern economics?
1. Quantification of human desire and behavior, and economic "laws" expressed through mathematics
2. A lot of hypothetical reasoning -- if/then implications which could possibly be turned into syllogistic form.
3. Descriptive and predictive, rather than being normative, though the predictions yielded by economics can be used in determining public policy/legislation.

So what does it mean to formulate distributism in economic terms? Through quantification? To yield what result/formula? Let's see how the rest of the book carries out this goal.

In the comments section, Dr. Médaille also writes:

Property itself, btw, is merely a means to an end; the end is distributive justice, namely that each man (and woman) gets the just fruits of their labor. Property properly understood leads to this result; property abstracted to an absolute becomes the opposite, a substitute for work. But property is not the only way of getting a just result.

This is interesting--I had not come across distributive justice being applied to the fruits of labor as well as to common goods.