One objection I often hear raised against thick libertarianism is that bundling libertarianism together with other values and commitments is dangerous to the cause of liberty, because a) it tends to alienate potential supporters of libertarianism who don’t share the additional values, and/or b) libertarians whose support for liberty is conjoined with an equally strong support for other values face a greater risk of being tempted away from their libertarian commitments by the possibility of using state power to promote the other values.
The first thing to point out about this objection is that it is not strictly correct to call it an objection to thick libertarianism. On the contrary, this objection is itself a version of thick libertarianism (we might call it “anti-thickness thickness”). After all, its objection to bundling libertarianism with other values is that such bundling makes the achievement and/or maintenance of a libertarian society more difficult – and that is precisely a thicklib kind of concern, specifically a form of what Charles formerly called “instrumental thickness” and now calls “strategic thickness.” After all, the non-aggression principle by itself doesn’t call on anybody to promote libertarianism; so as soon as one starts arguing that libertarians qua libertarians should reject X (where X is not by itself inconsistent with the non-aggression principle) on the grounds that X makes it harder to promote libertarianism, one has moved from thin to thick libertarianism. All that one can consistently do in defense of thin libertarianism is argue that libertarians need not bundle liberty with other values; to argue, more strongly, that they should not is to turn thicklib by bundling libertarianism with a commitment to no-bundles-but-this-one.
The fact that this purported objection to thick libertarianism turns out to express thicklib concerns itself is not a decisive reply, however; for the objector can simply redescribe the objection as directed against forms of thick libertarianism other than itself. Still, the skinnylibber who brings this objection has admitted the relevance of thicklib concerns, so we have our foot in the door.
Turning to the specific objections: it’s doubtless true that thick libertarianism alienates some potential pro-liberty folks who don’t like the extra values in the bundle; but it’s equally true that thin libertarianism alienates some potential pro-liberty folks who have trouble feeling the attraction of libertarianism until they see how it integrates with their other concerns. One simply has to weigh these considerations against one another, and against other thick concerns (not just strategic but also application, grounds, and consequence), to see how it all sorts out.
As for the worry that devotees of Liberty-plus-X might be tempted to violate liberty in order to promote X, well, so they might – but a commitment to X, if it’s the right X, might well help to guard against certain sorts of temptation to sacrifice liberty. (See, e.g., Rothbard’s argument that a rejection of utilitarianism makes one’s commitment to liberty more reliable.) If a commitment to X instead undermines one’s commitment to liberty, then either one has chosen the wrong X – one that is not properly bundled with liberty (and so one that is itself condemned on thickness grounds) – or else one has misunderstood the relation between liberty and X. After all, thicklib values are supposed to be ones that have a natural fit with liberty, values that it would be unreasonable or counterproductive to pursue by nonlibertarian means.
I’ve finally finished posting Francis Tandy’s 1896 individualist anarchist work 
I must gently point out that if an idea is inherently crazy when it shows up in the premises, it cannot suddenly become okay when it shows up in the conclusion (even if the conclusion is now derived from different premises). Or, equally, if it is okay in the conclusion, then it can’t be inherently crazy in the premises. In other words, when an idea (such as the distinction between positive and negative action) is all-pervasively presupposed in one’s policy proposals, one cannot coherently reject the distinction as part of the basis for those proposals.
Now in order to claim that there is no interesting metaphysical difference between A’s relation to F’s death and B’s relation to G’s death, one must in strict consistency also claim that there is no interesting metaphysical difference between C’s relation to F’s death and C’s relation to G’s death; C either makes a causal contribution (and we’re not talking about moral responsibility, just causal contribution) to both deaths or to neither. But no one (presumably) will seriously make such a claim. Obviously C makes an (inadvertent) causal contribution to F’s death but not to G’s. (To deny this, I maintain, is to fail to recollect the grammar of the concept of causation.) Hence there must also be a difference between A’s relation to F’s death and B’s relation to G’s death, QED.