I think John is a little too easy on Ross Douthat, because I do not believe that conservatism is a political philosophy. Conservatism is the practical principle that the pieces of furniture you have that suit and are comfortable should not be thrown away. And conservatism is a rhetorical mode of justification--effective on those who respect authority. But it isn't a philosophy.
DeLong presents this point as a criticism of what I wrote, but I'm afraid don't see it that way, since I don't think of conservatism as a philosophy either. It's a practical principle, yes, but I think a better way of putting it would be to call it an approach to political and social controversies, under which the fact that a given piece of furniture (i.e. a policy or institution) has suited in the past - and the fact that it is your piece of furniture, which belonged to your father and grandfather as well - gives the case for keeping it greater weight that it might enjoy if you simply tallied the chair or sofa's good qualities and compared them to the really fabulous, amazing, but still-hypothetical qualities of the fancy new one that might replace it. Now certain political philosophies may be effectively conservative in certain times and places, because they function as defenses of the existing furniture - thus Lockean liberalism is an effectively conservative philosophy in contemporary America in a way that it wasn't in the 17th century, and thus many contemporary American conservatives consider the Enlightenment, at least in its the Scottish and English manifestations, to be the patrimony that they're charged with defending. But conservatism itself (again, under my admittedly idiosyncratic definition) is not a philosophy or an ideology; it's an approach, a bias, or a political style.
DeLong goes on to quote an earlier post of his on the subject of Edmund Burke, whose conservatism he presents as essentially opportunistic and content-free:
Edmund Burke does not believe that Tradition is to be Respected. He believes that good traditions are to be respected. When Edmund Burke in his Reflections on the Revolution in France makes the argument that Britons should respect the organic political tradition of English liberty that has been inherited from the past, he whispers under his breath that the only reason we should respect the Wisdom of the Ancestors is that in this particular case Burke thinks that the Ancestors--not his personal ancestors, note--were wise.
Whenever Burke thought that the inherited political traditions were not wise, the fact that they were the inherited Wisdom of the Ancestors cut no ice with him at all. It was one of the traditions and institutions of Englishmen that they would conquer, torture, and rob wogs whenever and wherever they were strong enough to do so. That tradition cut no ice with Edmund Burke when he was trying to prosecute Warren Hastings. It was one of the traditions and institutions of Englishmen that all power flowed to Westminster. That tradition cut no ice with Burke when he was arguing for conciliation with and a devolution of power to the American colonists. It was one of the traditions and institutions of Englishmen that Ireland was to be plundered and looted for the benefit of upwardly-mobile English peers-to-be. That tradition, too, cut no ice with Burke.
But again, it's precisely because conservatism isn't a rigorous philosophy that it makes sense for conservatives to take a man like Burke as their hero - a practical politician who left behind no Second Treatise on Civil Government or Social Contract or similarly programmatic exposition of his views (in this vein, it isn't a coincidence that Russell Kirk's conservative canon includes very few programmatic thinkers), and whose conservatism manifested itself not in an ideologically-consistent resistance to change of any kind, but in an famously eloquent revolt against a particular noxious form of change, which threatened not only to replace a few pieces of furniture but to burn down the entire house in order to build a new one in its place. Similarly, two centuries later, many of my favorite conservative intellectuals - I mean the original neoconservatives, Jewish and Catholic alike - are figures who only began identifying as conservatives midway through their lives, when, as with Burke, changes they had supported gave way to changes that they didn't. The broader point is that DeLong's right, in a sense, to suggest that conservatism lacks "contents," though a more accurate way of putting it would be that there's no Platonic Conservatism in the way that thinkers from Locke to Rawls have attempted to describe a Platonic Liberalism, and there never will be. By definition, who is and who is not a conservative will vary from time to time and place to place, and what conservatives defend will vary as well.
But I confess to being a little baffled by how DeLong gets from here to the following all-caps outburst: "THERE ARE NO ATTRACTIVE MODERN CONSERVATIVES BECAUSE CONSERVATISM SIMPLY IS NOT ATTRACTIVE. DEAL WITH IT!!" I mean, fair enough, he doesn't like the contemporary GOP, which is where self-described conservatives tend to cluster in America these days, but surely his own definition - to repeat, "conservatism is the practical principle that the pieces of furniture you have that suit and are comfortable should not be thrown away" - implies that so long as at least some of our existing furniture is worth defending, at least some conservatives will be worth paying heed to.