Robert Nozick

Robert Nozick was an American analytic philosopher who contributed to the fields of epistemology, metaphysics, and political philosophy.https://iep.utm.edu/nozick/ Nozick is especially known for his work , published in 1974. Usually considered a right-wing libertarian, Nozick's interests shifted after publishing his most famous book, hardly ever touching political and moral philosophy again. Within epistemological circles he is better known for his tracking-theory of knowledge laid out in his 1981 work .
==Epistemology==
===Tracking theory===
Nozick is known for forwarding the tracking theory of knowledge, which is an externalist theory of knowledge that eschews the "justified" component in its analysis of knowledge. In his work Philosophical Explanations, Nozick defines knowledge as the following...
S knows that P iff...
#P is true. 
#S believes that P.
#Counterfactually, if P was true, then S would believe it. (sensitivity to truth)
#Counterfactually, if P were not true, then S would not believe it. (sensitivity to falsity) Nozick, Robert (1981). Philosophical explanations. Cambridge, Mass.: Harvard University Press. 
There are several advantages to this theory as it avoids the traditional objections to knowledge as true-justified-belief most famously problematized by It also evades various objections to causal theories of knowledge and broader reliabilist theories. Nozick dubs this theory's third and fourth conditions "tracking the truth" of a given proposition. Nozick is also extra careful to emphasize that the conditions of his theory are relativized to method so that S comes to believe or not believe P on the basis of some method M, and only the possible worlds to which S is using M to determine the truth of P are relevant; this is to prevent his theory from being too strict. This is all to keep the counterfactual possibilities under consideration restricted to only the method that S comes to believe P.
Nozick notices that in the instance of necessary truths such as "3 + 3 = 6", his theory would rule out such a proposition as being "known" since it could not be possible for the proposition to be false in any possible world. In those cases, only the sensitivity to truth condition applies.
===Rejecting the closure principle===
Typically the argument for global skepticism takes the following form...
Nozick acknowledges that his tracking theory seems to concede the skeptical argument because even if S were a brain in a vat, they would not be sensitive to the truth of being a brain in a vat. To undermine knowledge of the external world via truth-tracking using this argument, one would need to make two assumptions according to Nozick...
#That the counterfactual conditions of the theory quantify all logically possible worlds.
#That the closure principle is true.
Nozick rejects both of these assumptions, arguing that his sensitivity conditions only quantify the possible worlds with a minimal number of deviations from S's actual world. That is what makes them counterfactual.
The second rejection is far more controversial. The closure principle states that if S knows that P and S knows that if P then Q, then by knowing P, S would also know Q.https://plato.stanford.edu/entries/closure-epistemic/ Put another way, knowledge is transferable on known logical entailment. 
Nozick thinks it is possible to not know that one is not a brain in a vat, and know that one is experiencing the external world, so he rejects the closure principle and rejects the first premise of the skeptical argument above.
The philosopher Keith DeRose criticizes Nozick's rejection of the closure principle as resulting in what he calls an "abominable conjunction"; taking the idea that one can know P, know that if P then Q, and yet somehow not know Q to be absurd. DeRose, Keith (1995). Solving the Skeptical Problem. In Keith DeRose & Ted A. Warfield (eds.), Skepticism: A Contemporary Reader. Oup Usa.
There is a considerable number of strange logical implications of rejecting closure that Nozick himself spells out within his work. As an example, Nozick states that knowledge could not transfer over inferences of universal instantiation, or even conjunction elimination. This would mean that knowing that all foxes are cute, and knowing that Felix is a fox, would not allow you to conclude knowing that Felix is cute. Weirdly, you couldn't know that Alex went to the park and Emily went to the park, to just knowing that Alex went to the park. Such absurd restrictions on logical inference are why rejecting closure was untenable for DeRose. 
DeRose rejects interpreting the third and fourth conditions of tracking theory as being sensitivity conditions and rejects Nozick's rejection of the closure principle. Instead, DeRose takes a contextualist approach and restricts the set of possible worlds under consideration based on conservational context. Sometimes in considering alternative possibilities in whether or not we have knowledge, we do not seriously entertain the possibility of being a brain in vat -- unless of course, we are in the philosophy classroom.
===Rejecting the KK-Principle===
The , or KK-Principle, is the principle often used in epistemic logic that implies that in knowing P one would have to know that they know P. Tracking theory seemingly only grants S knowing they know P if they believed and tracked the truth of themselves knowing P. It would be consistent with the logic of tracking theory if S believed P, tracked the truth of P, but didn’t believe they knew P. Knowing P would not imply Knowing that one knows P.
Nozick recognizes this implication and defends it because the KK-Principle results in an absurd infinite progression of unique propositions. If KxP (x knows that P) implied KxKxP, then it would imply KxKxKxP, and KxKxKxKxP, and KxKxKxKxKxP, and so on. Nozick takes this as ridiculous. 
This would put Nozick at odds with some epistemic logicians, mainly whose system of epistemic logic implies the KK-Principle.
===Theory of evidence===
Nozick maintains that ideally, strong evidence for a given hypothesis should allow for a strict implication of that hypothesis so that subjunctively…
#If the hypothesis holds, then the evidence holds.
#If the evidence does not hold, then the hypothesis does not hold.
Nozick acknowledges that rarely do we find such strong evidence for a hypothesis so instead proposes that a probabilistic approach is more often applicable. This is what he calls the “weak evidence” case.
In the probabilistic case, Nozick takes it as permissible to infer the hypothesis iff…
#P(Evidence | Hypothesis) greater than or equal to .95
#P(Evidence | Null Hypothesis) lesser than or equal to .05.
Even then Nozick thinks there is an additional criteria in regards to competing hypotheses in that…
#P(H) > P(E | ~H).
Whereas H is the hypothesis, E is the evidence, and “~” is the symbol for negation.
This probabilistic approach to evidence and having deciding thresholds to when a hypothesis can be accepted mirrors that of hypothesis testing in science. It is not enough to simply have any kind of evidence to support a claim to make it acceptable. The evidence itself needs to suggest a higher likelihood of the claim being true than it being false. You also need to rule out equally as likely alternative hypotheses. If two conflicting hypotheses are equally likely in explaining a given piece of evidence, then there are no rational grounds to prefer one over the other. This is why we need to rule out alternative hypotheses within our scientific methods, instead of simply going with the one we initially proposed.
==Metaphysics==
===Closest-Continuer Theory of Personal identity===
Particularly relevant to philosophical questions relating to mind uploading, and personal identity is Nozick’s Closest-Continuer Theory. The theory states that Y shares the same personal identity as X if Y is the closest continuation of X and X is the closest predecessor of Y, provided that, no other entity exists that is equally close or closer to X than Y that can continue as X.
===Why is there something rather than nothing?===
Nozick treats this question as similar to “can everything be explained?”, identifying a problem in having an explanatory principle that explains why there is something rather than nothing, there is the problem of the principle itself needing to be explained. Nozick is sympathetic to the idea that the question is unanswerable but proposes multiple possible answers, none of which he is inclined to endorse. Explanations to why there is something rather than nothing arguably must relate referred facts to truth sentences that without simply re-asserting said fact in language, suggest the fact as consequence. Possible features of a correct explanation may include the model-properties of non-reflexivity, asymmetry, and transitivity. 
Option 1: Self-Subsumption
This possible explanation gives up the properties of non-reflexivity and asymmetry. An example of this would be a natural law explaining itself by simply having the inherent characteristics of being self-explanatory; this allows for the deduction that the proposition that expresses such a law is true. The problem arises arguably in explaining the existence of such an inherent characteristic.
Option 2: The Nothing Force
According to Nozick, inegalitarian theories argue that certain natural states do not need to be explained, but only deviations from said state. This is often explained by the application of a force negating that natural state. If we assume “nothingness” is a natural state and “something exists” is a deviation from such a state, then an identification of a force to transition us from nothing into something can be the potential explanation for why there is something. If nothingness is conceptualized as the negation of something or just ultimate negation, then it’s possible arguably that the ultimate presence of negation would forcefully negate itself creating something. Nozick dubs this the hypothetical “nothing force”.
Option 3: Fecundity
Under this option all possible worlds equally exist, so there is no “rather than” in this question as both worlds with something and worlds with nothing equally exist. This suggestion leads to natural worries to why any possible worlds exist at all, and given that is a deflatable worry there is still the question of why we exist in a world of this particular type with unifying natural laws rather than one with disjunctive independent laws.
Further questions result from inquiries to these possible responses. Nozick in particular wonders if the requires some explanation. Meaning that the principle of sufficient reason requires sufficient reason to justify itself. The absence of which may in turn be an extension of the initial question, or if such reason isn’t needed — a possible refutation of the principle of sufficient reason. This may lead one to entertain “weaker” and “stronger” notions of the principle of sufficient reason that dictate what exactly it applies to if it cannot itself be explained.
===Defense of mystical experiences===
Questions related to the former metaphysical quandary explored in the last section lead Nozick to point out how what seems exhaustive of possibilities may not genuinely be exhaustive, and so, a false dichotomy. An example he uses is “coloured and uncoloured” as it seems exhaustive but is the number 5 coloured or uncoloured? What about the concept of truth? Likewise, the very dichotomy of “existence and nonexistence” itself may not be exhaustive. Much like the example of colour, such a dichotomy may rest on a presupposition, just as “coloured or uncoloured” rests on the presupposition of referring to particular concrete objects, rather than abstract objects (i.e. numbers, sets, etc.).
Nozick then takes this all to suppose that in the description of mystical experiences, such as those induced by the use of psychedelics, through meditation, or the experience of trance-like states often described as “beyond known possibilities or description” could have a rational basis. He then goes on to chastise skeptics for being so arrogant to assume that we know what the exhaustive state of possibilities is. Nozick takes it as intellectually dishonest that we would dismiss spiritual and/or mystical experiences on principle.
The value of the above argument has a mileage that may vary depending on the person receiving it, but that is seemingly true with most, if not all, of Nozick’s philosophical arguments.
==Political philosophy==
===Critique of Rawls===
Both and Robert Nozick are treated as the faces of political philosophy in the analytic tradition. Prior to the 20th century, political philosophy had been dominated by the continental tradition, barring a handful of political essays written by Bertrand Russell, and not disregarding Karl Popper’s political work .
The influence of Rawls’ was substantial, and is a mainstay within college courses on ethics. In a very real sense Nozick’s was a reaction to Rawls — a libertarian response to Rawls’ liberal egalitarianism.
Rawls came to determine the principles of Justice from what he called the “Original Position”. Rawls, J. (1971). A theory of justice. Belknap Press/Harvard University Press. The “Original Position” is the basis to a social contract. A thought experiment that imagines all members of society coming to an agreement to what constitutes a society based on fairness, with the agreement itself being under the pretext of equal status for all participants, i.e. no threats, unequal positions of power, filibustering, etc. https://plato.stanford.edu/entries/rawls/ 
An important element to this original position is “the veil of ignorance” which places each participant in total ignorance of their own sex, gender, race, class, talents, etc., as well as, the overall class structure of society and existing political systems.
This is to ensure that the principles of justice are decided upon as first principles without arbitrary preference. Rawls’ thought that naturally, rational actors under the veil of ignorance would come to agree upon principles that would ensure equality of opportunity and equal access to resources, as well as, ensuring that any social or economic inequalities that result overtime work to maximally benefit the least well off.
It is not difficult to see how on the basis of determining first principles of justice, one would come to reason in support of things like redistribution of resources, and government regulation in the economy. Things that are big right-libertarian no-nos. This is what motivates, in part, Nozick’s objections. 
Nozick’s political philosophy treats individual rights as sacrosanct and paramount. He derives his concept of rights from Lockean natural rights, and the second maxim of Immanuel Kant’s categorical imperative — the whole “one should treat persons as ends within themselves, rather than a means to an end” thing. Which is plenty ironic for a philosopher who unapologetically supports free-market capitalism
Nozick takes individual rights as being primarily rights of ownership, and rights to act without interference. One has a right to their self, their body, their labour, and their property. Put more specifically by the Internet Encyclopedia of Philosophy…
This conception of rights is used to ascribe wrongness to involuntary slavery, unprovoked killing, theft of someone else’s possessions, and of course, taxation. Nozick concludes taxation is morally illegitimate, not simply with the motto "taxation is theft”, but what is in effect, forced labour akin to slavery — on the basis that it makes the income collected via the result of uncompensated labour. Why this doesn’t also apply to the capitalist’s profit from surplus value is a mystery. On the other hand, maybe we can restrict the description of slavery to actual chattel slavery. Just a thought. 
This highlights a point of contention between Rawls and Nozick, as Rawls would argue that the principles of justice rationally decided under the original position would entail the state having the right to redistribute wealth via taxation. Nozick not only seeing taxation as immoral, also believes the concept of “redistributive justice” to simply not be justice at all. Nozick prefers his theory of justice as one of “entitlement”, granted via the acquisition of resources through one’s labour provided the resources they use wasn’t stolen; for Nozick, there is no prior distribution of wealth for the state to redistribute to, so it is just in essence, theft of people’s property.
There is, of course, a deep irony in the way Nozick conceptualizes justice. Nozick believed that one was morally entitled to the fruits of their labour, their selves, and the property that was transferred to them voluntarily by the previous owner. Acquisition of someone else’s property or resources that was acquired involuntarily rules out moral entitlement and is in fact unjust in Nozick’s view.
Which makes the fact that he is an American philosopher …well…awkward. What is the moral entitlement of white settlers currently living on stolen indigenous land? What about the swathes of property and infrastructure that only exists due to involuntary prison labour? Davis, A. (2003). Are Prisons Obsolete? Seven Stories Press. Nozick himself cites a principle of rectification in his concept of justice, settling past injustices through the use of acquisition and transfer. Interestingly enough, Nozick believed that the historically dispossessed (Marx's property deriving from "conquest, enslavement, robbery, murder"Capital: A Critique of Political Economy, Volume 1 by Karl Marx (1990 [1867]) Penguin. ISBN 9780140445688.) deserved some sort of compensation, thus broaching the rarely-discussed in libertarian circles issues of negative externalities.Adventure Capitalism: A History of Libertarian Exit, From the Era of Decolonization to the Digital Age by Raymond B. Craib (2002) PM Press. ISBN 1629639273.
Nozick by and large within the work of Anarchy, State, and Utopia largely concerns himself primarily with explaining why billionaires are entitled to their wealth. The argument for rights and entitlement justice is used mostly as a basis to argue why minimum wage and rent control are immoral — because people have the “right” to charge whatever they want for the use of their property.
This interest in explaining how billionaires are morally entitled to their wealth is best exemplified by Nozick’s “Wilt Chamberlain” thought experiment, again best described by the IEP…
This thought experiment both serves to illustrate the falsity of Rawls’ theory of justice and doubles as a defense for capital. There are obvious problems with this thought experiment if intended in that way.
Writing in 2011 for Slate, social commentator Stephen Metcalf had this to say about Nozick’s argument…
The “Wilt Chamberlain” thought experiment, as an argument for capitalism, is fairly weak, and as a critique of Rawls, it also fails to really illustrate what exactly is in conflict between Wilt Chamberlain getting paid an extra 25 cents from each basketball fan and Rawls’ idea of the original position. Rawls’ stance on justice does not seem to exclude the possibility of people making a lot of money due to their unique talents. As an argument for capitalism, it does not even address the elements deemed essential to capitalism that opponents object to.
If one were to be a skeptic about the existence of human rights outside a mere legal fiction, the argument Nozick provided would be in no way compelling. More so, if one believes there are greater moral duties than individual liberty. Nozick’s argument would exclude any government action towards climate change given the moral absolutism applied to individual property rights, and his total opposition to government intervention in the free market.
===Critique of the "anarchist"===
The “Anarchy” that Nozick was writing about in particular was not mainstream anarchism as developed out of the 18th and 19th centuries, but instead anarcho-capitalism. With the degree to which individual economic rights are taken as seemingly the only morally relevant basis for anything in Nozick’s view, it would seem that voluntarism and anarcho-capitalism is the only thing that follows. This would be wrong. Nozick seemed to recognize what many ancaps don’t, in that, property rights and contractual agreements would be pretty hard to enforce without a government to enforce them.
Nozick argued that in the interest of non-violent resolution and ensuring that contracts are fulfilled “different agencies” would get established to fulfill that role. To ensure cooperation these agencies would inevitably have to network, and then unite into an overarching framework resembling federal government. https://plato.stanford.edu/entries/nozick-political/ This becomes the basis for where Nozick argues in favour of minarchism or the “night watchman” state.
Ancaps object that this role can be served best by protection rackets businesses, whose role would ensure adequate compensation for violated property rights. If a state performed and monopolized that function instead, then that would violate the rights of individual businesses that should be able to seek a private option. This is similar to the libertarian objection to public education. Nozick actually concedes this point believing that property rights that can be compensated ought to be compensated by private protection firms; the problem is that not all property violations can be compensated. Think for example of how one gets compensated for being murdered, seriously maimed, or knocked into a coma. It is in this case that Nozick thinks the duty falls upon the night watchman state. A broken arm may be a subject of liability rules, but to hold the wrongdoer accountable for compensation, or even to prevent the threat of breaking arms being used as a coercive strategy, you need some kind of external rule enforcement apparatus. A disorganized collection of competing “protection businesses” probably would not be sufficient in fulfilling that role. 
All of this is particularly strange considering the extent to which Nozick treats the rights of the individual as paramount. Violations of a person’s rights entitle them in Nozick’s view to seek compensation, or even to have punishments implemented on the wrongdoer; but not, permission to violate the wrongdoer's rights in turn. How is it then that these compensations/punishments get enforced without violating the rights of the wrongdoer as a “self-owner”?
Heavy emphasis is placed on the “consent” of individual actors, affirming Kantian claims about the impermissibility of individuals being used as means to an end (though in Nozick’s case being used as a means without their consent). Seizing the fruits of another’s labour without their consent is a violation in Nozick’s view. Kantian moral law prohibits the exploitation of individuals. This is where a seeming logical inconsistency exists in Nozick’s entire political philosophy. 
It is just assumed that the agreement between tenets and landlords, or employers and employees is uncontroversially consensual. If it is under a context in which someone has no realistic choice outside of paying rent to a landlord or being homeless — then the agreement is being made under the context of situational coercion. Regardless if the landlord themselves is the source of coercion, the consent is not by any means freely given. 
As a thought experiment imagine that situationally you are under the threat of being beaten up by an unkind stranger if you do not get a haircut. Coming to a hairdresser, you get your haircut in hopes to avoid getting beaten up by the aforementioned stranger. The hairdresser is a third party in this situation but is aware of your circumstance. They don’t seem to care, and in fact, think of the situation as ideal because they have more leverage to charge whatever they want for the haircut. Would you say your decision to get a haircut was voluntary? Would this hairdresser not be treating you as a means to an end? 
If you’re inclined to still say that the decision to get a haircut was voluntary, imagine instead that the situation was to provide a third-party sexual favours. To say that such an act of sexual exploitation was consensual reflects the most egregious components of rape culture. As extreme and traumatizing as that example may be, affirmative consent does not solely apply to sexual activity. It is no less a violation for someone to vandalize your home, forcibly buzz-cut your hair, or park in your driveway without permission.
Likewise, it is no less voluntary to agree to pay rent under the threat of homelessness. Having no access to means of production yourself, or accessible means to self-employment, if you must work for an employer as a wage-labourer to pay for said rent extending that threat of homelessness — then that too is no less involuntary.
And in both cases, you are in some sense giving up the fruits of your labour to some capacity to both your landlord and your employer. This involuntary agreement is all the more likely under a minarchist system if there is no source for publicly funded housing, welfare support, or guaranteed equality of opportunity.
Left-wing individualist anarchists recognized as much, and categorized such dynamics as akin to the immorality of taxation. Hence, profit is theft. Regardless of the legitimacy of that position, If Nozick was consistent regarding his views on individual rights, consent, and Kantian maxims of individuals as ends in themselves — then he couldn’t consistently be a free market capitalist. You do not need to be an anarchist either to recognize that this political philosophy isn’t internally consistent.
==Critique of Utilitarianism==
Like Rawls, Nozick was interested in attacking the moral theory of utilitarianism. This is because utilitarian ethics would grossly undermine his political theory, allowing injustices to be acted against an individual, or minority group, for the “greater good”. The conflict between utilitarianism and justice, goes at least as far back as the writing of . Mills himself seem to think that the concept of justice only mattered in so much it maximized utility. Mill, J. S. (1863) Utilitarianism. London, Parker, son, and Bourn. [Pdf] Retrieved from the Library of Congress, https://www.loc.gov/item/11015966/.
===The “Experience-Machine” thought-experiment===
Recall that utilitarianism takes what is morally good as that which maximizes pleasure for the greatest number of people. Though in some iterations an important addition is the minimization of pain. Utilitarianism can be differentiated between act-utilitarianism and rule-utilitarianism. Act-utilitarians believe that every action must be performed to the maximization of pleasure, while rule-utilitarians believe one only need to follow rules that if enforced and acted upon generally maximizes pleasure. These would be examples of positive utilitarianism, which is based on presupposition of hedonism.
Nozick thought experiment specifically challenges hedonism and positive utilitarianism. The thought experiment simply proposes the opportunity to enter a fool-proof simulation where the brain would be forced to have nothing but positive experiences. You wouldn’t be able to tell you were in a simulation, it would be as if your life from there on out was nothing but a series of positive life experiences. If given the opportunity to spend the rest of your life simulated within this experience machine, leaving your past life behind, having no memory or knowledge of having put yourself in this machine, would you? You could even have the ability to dictate what types of experience you would have prior to entering the machine.
Nozick is inclined to think that many people will answer no, and he thinks they have good moral reasons to make that decision. Hedonistic Utilitarianism on the other hand, would dictate that we would all be morally required to enter this machine so as to maximize utility.
Nozick takes it that we may refuse to enter the machine on the basis we value having real impacts on the real world, that our relationships with real people cannot be replaced by simulations, or that we do not have the capacity to develop into a memorable person in of ourselves if we don’f exist actively in the real world. Nozick frames this an argument against the hedonistic principle of positive utilitarianism via modus tollens…
The hedonistic principle in this case would be the idea that pleasure is the only thing to have true moral value. Nozick thinks the common reasons why we would object entering the experience machine directly imply that there are things of moral value besides pleasure, (i.e. having a legacy on the real material world). 
The hedonistic principle was espoused by utilitarians historically, such as the aforementioned John Stuart Mill, and . Contemporary examples would include the likes of 
Sam Harris, especially within his 2010 work .
===The “Utility-Monster”===
Another thought experiment Nozick proposes is the thought experiment. This one exploits the limitations of the by proposing a hypothetical person who experiences many times as much pleasure from an individual act compared to anyone else (possibly everyone on the whole). Positive utilitarianism would mandate the redistribution of resources to this hypothetical person over others so as to maximize utility. Nosick proposes this can be complicated further if this hypothetical person dubbed a utility monster, experienced immense pleasure from the suffering of other tenfold the suffering caused. Nozick alleges that a consistent utilitarian would then have to act in the suffering of countless others to achieve the maximized pleasure of satisfying the utility monster.
===Kinds of utilitarianism unaffected by these objections===
These two thought experiments primarily work against positive hedonistic utilitarianism, but not so much for other sub-types of utilitarianism that don’t work in the maximization of pleasure. Negative utilitarianism as an example only concerns itself with the minimization of pain and/or suffering. The minimization of suffering with no concern for the maximization of happiness and/or pleasure, would allow the negative utilitarian to ignore the threat of utility monsters. 
Negative utilitarians may still be subject to the objections of the experience machine, if such a machine can be designed to eliminate the experience of pain and/or suffering.
Preference utilitarianism, which concerns itself with the satisfaction of the greatest number of preferences for the greatest number of people can arguably avoid both utility monster and experience machine motivated objections against utilitarianism.
==References==