Wednesday, September 19, 2012

Darwin, Metaphysics, and Natural Kinds: What is a Species?


Samir Okasha's Darwinian Metaphysics: Species and the Question of Essentialism

Key terms
Intrinsic property: the necessary property/ies that make a thing what it is.   Usually it is considered to be part of the things microstructure but not necessarily.  E.g. An intrinsic property of a car is that it has 4 wheels and an engine. An intrinsic property of water is that its chemical structure is H20.
Essentialism (about kinds):  The idea that things have essences that make them what they are.  This is often used interchangeably with intrinsic property.  For example, what makes the kind 'dog' is that all dogs have the essence of "doggyness".  This could also be explained by properties like characteristic behaviours, DNA, or form.  Aristotle classically declared that the essence of 'man' is rational thought.

Introduction
In virtue of what is my wiener dog a member of Canis familiaris? Is there some intrinsic essential property that he and all other members of the species posses? It seems like there is so much variation between 'breeds' that it'd be difficult to find a group of properties that all dogs have.
Okasha takes essentialism to be the position of Kripke, Putnam, and Wiggins—i.e., that the concept of kind essentialism used in the hard sciences also applies to biological kinds. Okasha suggests Putnam and Kripke (PK) are mistaken to apply their brand of essentialism to biological kinds because (a) of facts about evolutionary biology that don't apply to the hard sciences, and (b) the purpose of classification in biology is different from that in the hard sciences. However, it is not all doom and gloom for the PK model: if instead of demarcating kinds according to intrinsic properties we use relational properties, aspects of the PK model can be salvaged.

Philosophical roots and overview of the Putnam/Kripke (PK) Essentialism
The philosophical origins of the PK essentialist model can be traced back to Locke's distinction between the nominal and real essence of a kind. The nominal essences are the macro-properties of an object that we pick out to determine the group to into which we place it. The standard example is that the nominal essence of gold is that it is shiny, metallic, yellow, and malleable. The particular properties we settle on to define kinds are conventional; that is, they are not dependant on anything intrinsic to the particular things we are classifying, rather they are selected based on utility and/or accidental facts about our perceptual system. For example, we could have grouped objects according to gross size and texture, but this would not have served any useful purpose.
In contrast to nominal essence there is the real essence which is the (intrinsic) hidden underlying microstructure which is causally responsible for nominal essences. If we could access the real essence of objects, we'd be able to group them according to their intrinsic properties/”hidden structure” and therefore their metaphysically real (as opposed to conventional) kinds. Locke didn't anticipate our having “microscopic eyes” to actually identify real essences, so he supposed all kinds would be nominal.
Of course, science has progressed to the point in the hard sciences where microstructure can be identified, as so objects can be classified according to (real) kind. PK natural kinds emerge out of this reality. The standard examples of PK essentialist kinds are “gold is having the atomic number 79” and “water is having the chemical composition H20”. So, determining whether something is a kind is an empirical matter. For example, to determine whether H20 is a kind is a matter of verifying that all samples of water have the molecular structure H201.
Another important way the PK model diverges from Locke is over the “semantic inertness” of real essence. Whereas Locke thought that speakers when using kind terms were only referring to nominal kinds, PK hold that even without knowledge of real properties speakers imply that their kind-terms refer to the real properties causally responsible for the observed properties2. There is little disagreement that this model applies to chemistry, however, the debate between PK and Okasha is about whether we can extend the “hidden microstructure” model of kinds to biological kinds.

Arguments Against Using the PK Model for Biological Kinds
Okasha suggests two main lines of argument that lessen the probability that PK essentialist notion of kinds is applicable to evolutionary biology. The first line of argument is empirical which can be generally framed by referring back to Locke's observation that there is no principled way to distinguish between accidental and intrinsic qualities. Given that evolutionary theory doesn't restrict the possibility of changes (i.e., mutations, meiosis, and genetic recombinations) to any aspect of an group of organisms' phenotypic or genetic properties, it seems unlikely that a kind could have an immutable intrinsic essence. With no necessary enduring intrinsic property (that isn't also shared by other kinds), what type of property could defines the kind?
A loose analogy to illustrate the problem would be to try to classify liquids according to their shape; obviously, it will change depending on its environment. Another problem with biological kinds that arises out of empirical considerations is that often intra-species genetic and phenotypic differences can be greater than (closely related) inter-species differences. So, if there can be more differences within a kind than without, on what grounds can we construct kinds that are based on common intrinsic properties?
The conceptual argument again relates back to Locke's operationalism. Even if a set of (genetic/phenotypic/genotypic) properties were shared by all members of a kind and by no non-members, we would not consider having these internal properties necessary to membership. Suppose two members of a species produce an offspring lacking in one of the essential properties. We would probably still group the offspring with its parents.
So, it looks like the (internal) essentialist model for kinds doesn't fit well with the ephemeral nature of species in evolutionary biology. Should we then completely abandon the PK model in relation to biology? Okasha suggests that the PK model is still applicable to biological kinds so long as we relinquish the requirement that essential properties of kinds be intrinsic and instead replace them with relational properties.

Relational Kinds: Retooling the PK Model for Biology
A Relational property in this context means the essential property relates x to other xs. The relation is the property that tells us “in virtue of what organism x is a member of kind y”. In addition, an essential relational property cannot be shared by non-xs. Biologists use four basic relational properties to define species concepts: phenetic, interbreeding, ecological niche, and phylogenetic. While all 4 methods have their weaknesses, the phenetic concept is considered the weakest because it suffers from the same problems as internal essentialist concepts. Furthermore, a peculiarity of the relational species concepts is that two organisms could be molecule for molecule duplicates, but if they don't the share the relational kind property, they are considered to be of different species3.
Is this a big problem? I'm not sure. We could defend the relational view and say that there is an extremely low likelihood of there being two or more co-existing molecule for molecule duplicates that don't bear the same kind relation so we shouldn't worry about this problem. On the other hand, maybe the existence of the logical possibility of this counter-intuitive outcome of relational kinds is evidence of a problem. The reply to this worry is that just because the logical consequence of the relational-concept kind is counter-intuitive doesn't mean there's a problem—it only tells us something about our intuitions. There is no logical problem with relational kinds so long as we can accept the counter-intuitive consequence, so we shouldn't worry.
It seems that with the substitution of relational for intrinsic properties, the PK model can be applied to biological kinds after all. The PK model can maintain the semantic role of kinds terms because now we can say that speakers who use the terms are intending to refer to some essential property beyond superficial appearances. Unfortunately, the applicability ends here because the PK model also implies that the essential property of a kind (its hidden structure) is also causally responsible for its superficial properties. While this is true of chemical kinds, this isn't necessarily the case for biological kinds. An organism's belonging to a particular chunk of the genealogical nexus (or occupying an ecological niche, etc...) isn't the proximal cause of its superficial properties—there is only an indirect causal relationship.
For these reasons Okasha concludes that the PK model is only half-right when applied to biological kinds. On the PK model essences play both a semantic and causal/explanatory role, but “there is no a priori reason why the same thing should play both of these roles4.” While I agree with Okasha here I think there is something a little disconcerting about decoupling these two roles. It appears we lose a degree of objectivity and predictive power.

The Purpose of Kinds and Worries About Decoupling Essences from Causal/Explanatory Roles
The fact that there are so many different species-concepts can raise worries about conventionalism. Why should we consider one species-concept over another? Consider that mammals are often grouped according to either phylogenetic or breeding or ecological niche concepts but bacteria are grouped according to degree of variability in section (?) 16 of sRNA. If one strand of bacteria has greater that 1% variability from its “parent” strand then it is considered to be a new species of bacteria5. Clearly, biologists are picking and choosing their species concepts based on what is useful to their research aims (and contingent upon the sophistication of their measurement techniques). If biologist were really classifying according to essential kinds, why isn't there just one concept of species?
This isn't necessarily a problem, but seems there is a lot more lateral flexibility in relational kinds than there is with intrinsic kinds, such as in chemistry. That is to say, organisms can be grouped into kinds various different ways at the same “level of grain”, whereas the microstructure of chemical kinds is more restrictive in respect to method of classifying at that grain. Furthermore, it seems that organizing according to intrinsic properties provides a greater ability to make predictions about the properties of kind than you might make with relational kinds in biology. However, given the nature of evolutionary biology, I'm not sure there is a choice in the matter since--as has been shown--defining biological kinds according to intrinsic properties is a non-starter.
This brings us head to head with the final issue I wish to discuss: what is the purpose of a classificatory system? On the PK model it seems that the implicit answer to this question is that kinds are meant to be scientifically useful; viz, “to provide the greatest possible predictively useful generalizations6”. Predictively useful generalizations usually require we know something about the kind's causal structure. But in biology we don't have this information, nor do we need it because it has a different purpose of classification.
The purpose of classification (i.e., species concepts) in biology is to identify “units which we believe play an important role in the evolutionary process7”. Of course, knowing an organism's species (defined in one of the relational concepts) does provide the ability to make predictions about behaviour and morphology, but, again, this is not the primary purpose of having the classification.

Concluding Thoughts
To conclude I think it's interesting to consider how species concepts are defined and why one would be used over another in a particular situation. There seems to be an interesting reciprocal relationship between the empirical and the analytic concepts. The species concepts are analytic but they are informed by empirical considerations. Consider the breeding concept. Certainly, whether one group breeds with another is a matter of empirical observation but the decision to define a kind based on a particular concept of inter-breeding rather than another is analytic. However, that particular kind concept will also have been shaped by past empirical observations. At some point, the biologist has to “break in” with a an imperfect concept. The relationship between the analytic and synthetic in the context of natural kinds is something I'm interested in exploring more, so I encourage comments on this issue!


1Okasha, p. 193.
2Ibid, p. 195.
3Ibid, p. 201.
4Ibid, p. 203.
5Chana Palmer-Davis, world famous geneticist and my sister.
6Ibid, p. 209.
7Ibid.

Saturday, September 8, 2012

Mill's Utilitarianism Part 3: Proof of the Principle of Utilitarianism

Mill's Utilitarianism, Chapter IV:  Of What Sort of Proof the Principle of Utility is Susceptible

Note: For criticisms of Mill's Proof see my later posts "Sidgwick's Criticisms of Mill's Proof" and "Moore's Criticisms of Mill's Proof"

Favorite Quote: "...[Virtue] may be felt a good in itself, and desired as such with as great intensity as any other good; and with these differences between it and the love of money, of power, or of fame--that all of these may, and often do, render the individual noxious to the other members of society to which he belongs, whereas there is nothing which makes him so much a blessing to them as the cultivation of the disinterested love of virtue."

Background
A familiar theme in many branches of philosophy (mostly epistemology) is how to prove a primitive.  By "primitive", I mean a foundational fact.  A fact that to the question "why?" you can't reply anymore than "it just is".  Think of it this way:  Imagine you're taking to a really annoying kid who keeps asking "why" to every successive answer you give.  At some point, you're going to run out of answers.  Or punch him right in the face!!


Here's an example of a conversation reaching a primitive (from a criminally underrated comedy):
Example of an Epistemic Primitive(video)

So, what's all the hoopla about primitives?  Well, Mill has a problem with proving utilitarianism because it is claimed that its first principle (ie. an action is good to the degree that it maximizes happiness for the greatest number of peeps) is a primitive.  But so are the first principles of any moral system.  If proponents of each moral system each tell me I should accept their particular first principle because "it just is the right one", why should I choose one system over another?  And on what grounds?

Mill recognizes this problem and tries to give us a proof...

Proof of Happiness as the Only Good
We begin with what Mill sets out to prove: that in human affairs, happiness is the only desirable end.  Not that we don't want other things, but that we want other things like money, honor, success, friends, and family because they are often only means to our ultimate end, which is happiness.  But why should we agree with this?

First argument:  How do we know if something is visible?  People see it.  How do we know if something is audible?  People hear it.  So...how do we know if something is desirable?  You got it...people desire it!

Ok, so people desire their own happiness perhaps, but it doesn't necessary follow that people desire the happiness of others...

Baaaat! That's not what we're trying to prove.  We're not primarily concerned with what people actually do, we are concerned with defining what moral goodness is.   The fact that a person values and desires their own happiness tells us that happiness is a good to that person.  So, the general happiness must be a good to the aggregate of all persons.

So far we've (more or less) established that happiness is a good because it is the desired end of most people's actions, but we have yet to establish that it is the only good.  To do this we have to demonstrate that happiness is the only thing that people desire.  It seems clear that there are other things people desire such as virtue (some people), absence of pain, and absence of vice, makin' paypur, range rovers, etc...

So, how does Mill argue for his postion?  He could say that all the other things people desire are instrumental ends; that is, they are merely a means to happiness.  But no, that'd be a cheap move and open him to some easy challenges.  Instead, he pursues a slightly different (but similar) strategy.

He acknowledges that for some people, they actually do pursue virtue, money, fame, etc... not as means to happiness but as ends in themselves.  So, how is that consistent with happiness being the only ultimate end?

The answer is that although people might not pursue virtue and such as a means to happiness, but as a component of happiness.  Huh? Wut?  How does this work?  

Lets drawr an analogy with money.  Most people pursue money as a means to some end.  People pursue money cuz it will get them the things they really want.  In the standard case, money is an instrumental end.  It is simply an intermediary step on the way to getting what we really want.  But, sometimes, in the course of some people's lives, they start to want money just to have it.  They don't use it to get other things. They want money for money's sake.  They like to love it and feed it and pet it...This is usually a progression.  It doesn't happen over night.  Not that it would matter if it did.  The point is, that somewhere along the line some people pursue money just to have money.  Having the money--by itself--makes them feel happy.

Ok, lets go back to virtue.  Most people typically act virtuously because helping other people makes them feel good.  If they didn't get a good feeling from acting virtuously, they might not so act.  But, hopefully, some people over time will start to value acting virtuously just for the sake of it.  Why?  Because this has become an element in the set of things that make them happy.  Being virtuous makes them happy.  Just like simply having money makes some people happy.

The difference is subtle.  In the first instance we are virtuous, not because we have a desire to be virtuous, but because acting so will afford us some pleasure; that is, we seek the consequence of 'pleasure' from the consequence of our virtuous act.  Over time, acting virtuously itself becomes a source of pleasure.  We get a warm fuzzy feeling from helping people.  What kind of people?  People that need help!  And so, virtue becomes a component of what is considered to be pleasure/happiness.  It gets included in the umbrella of things we equate with happiness, and thus, "good".

I have to admit, I find this a little sophistic.  Here's another quick example that might make strengthen Mill's case.  Few people listen to music because they figure the end result of doing so will bring them happiness.  Instead, for many people music is an element in set of things that are happiness, thus becoming a good in itself.  Music is happiness--or at least listening to it is.  And being virtuous (for some) is a direct source of happiness.  Acting virtuously is simply included in that person's definition of what it means to be happy.

So, because things like music and virtue, in themselves, come to cause us happiness, they become goods in themselves.  But why are these things goods?  Because they produce happiness...Ah ha!  So, you see...we've come full circle:  that which brings about happiness is good--be it virtue or music, and  whether we seek it as a means or an end!  And what's more, this proves what we've been trying to prove all along, that "there is in reality nothing desired except happiness."

It's an interesting thought experiment to come up with a counter example.  Is it possible that someone would listen to music if they thought it would make them unhappy?  That's probably a bad attempt at a counterexample.  Lets ax instead if it's possible that someone would act virtuously if they expected it to make them unhappy.

Possibly.  But the utilitarian would reply that the arbiter of goodness isn't a particular individual's happiness but the total happiness produced.  So, we need to re-ax the quextion: (Hai! Ya!) Would someone self-sacrifice if they knew that it wouldn't increase the happiness of others or at least prevent their suffering?  On what grounds would they be acting?  I suppose it's possible but it certainly would appear strange.  Not that humans don't already engage in a crap load of strange behaviours.  But I digress...

So where we at?  Oh right.  Proving that happiness is the only thing that human's desire.  Why is happiness the only thing humans desire?  Because the ends of our actions are all either directed at something that we consider to be part of happiness or a means to happiness.

Now here's the part that's a little sketchy.  The first premise we've established is that (1) The only thing that humans want is things that are a part of happiness or are a means to happiness.  From this it follows that (2) these are the only desirable things.  The next premise I'm not sure where it came from, he just kind of sneaks it in: (3) "the promotion of happiness is the test by which to judge all human conduct." Then Mill concludes (C) "it necessarily follows that it must be the criterion of morality, since a part is included in the whole."

What I don't see is where (3) comes from.  It looks like it's supposed to follow from (1) and (2), but there is no logical connection as far as I can tell.  What er'body wants and the benchmark for evaluating the moral worth of actions are not necessarily connected.  As a "gentle" Christian once told me, "children in hell want ice water."  Doesn't mean the standard of conduct should be measured by how much ice water is produced... The obvious response is to ax why they wanted ice water: to bring them relief from suffering (same as pleasure/happiness for a utilitarian).  So, check mate!  Utilitarians win again.

Mill would probably futher respond that, "you dumbass, we've just spend a crap load of ink and paper proving what 'good' is.  'Good' is whatever produces happiness.  More happiness= more better.  So, a good (i.e., morally right) action is one that produces the most happiness for the greatest amount of peeps.  Eazy peezy japonese-y!

Happiness is goodness!  That's what good is!  And there is only one good--happiness.  Were you asleep or something?"

Or something like that.  He could be quite short with people that questioned him.

That's all for tonight.  I hope this made you happy...meaning it was good!


Sunday, September 2, 2012

Mill's Utilitarianism Part 2: Mill's Argument for the Ultimate Sanction (What Can Compel Us to Consider General Happiness when We Act? )

Yo check it.  Weez about to learn about why (Mill thinks) we should be compelled to adopt and adhere to utilitarianism as the ultimate moral standard.  That is, why does a utilitarian ethic have binding force?

Overview and RecapOk, so...like...'member utilitarianism?  It's the idear that the moral goodness of an action is proportional to the total amount of happiness (or pleasure) it produces (for the agent as well as--and especially--other people).  So, an action that produces more pleasure/happiness for 5 people is more gooder than an action that produces pleasure/happiness for only 1.  Simple enough so far, right?  (We'll table some of the problems to get to the point of this post.)

Next step--Definition:  Happiness and pleasure are one and the same for utilitarians so I'll just say happiness to mean both; happiness also includes avoidance of pain.  But Mill makes a distinction between types of pleasure: higher (intellectual) and lower (sensual).  We know some pleasures to have more worth than others because the majority of peeps who experience and have the capacity for both will choose the higher over the lower.

Ok, supposing we accept everything so far, there's still a prollem--why should I be motivated to obey this standard of morality?  What's stopping me from being a selfish egotistical misanthrope and stepping on others to feed my own ravenous appetite for pleasure?  That's the problem Mill tackles in this section...

Of the Ultimate Sanction of the Principle of Utility
People Will Act on Utilitarian Principles Because They Already Are UtilitariansThe general gist of Mill's argument for why we should be motivated to obey the utilitarian maxim and whence it derives its motivating force is that we are already utilitarians and this is the natural moral position!  Of course he has some more specific arguments to support this assertion which we will look at...

Mill sets things up for his we're-utilitarian-even-if-we-don't-know-it view like this:  Many people recognize a moral duty not to murder, steal, and deceive yet might question the utilitarian maxim to act according to what will promote the general happiness.  How do we explain the feeling of moral duty toward abstaining from these specific acts while there is no corresponding feeling to act on the utilitarian maxim?

Mill suggests that we have accepted the specific consequences of utilitarianism but not the general maxim.  But this failure is simply a consequence of poor education and lack of influences which form moral character.  If people got their learn on, the 1st principle of utilitarianism "shall be as deeply rooted in our character, and to our own consciousness as completely a part of our nature, as the horror of crime is in an ordinarily well-bought up young person."

Basically, people who accept the consequences of the utilitarian ethic but not its principle do so because it falls outside of their particular custom and education--and so they question it.  But this is nothin' a little learnin' can't fix.

The obvious problem with this argument is that it can be made by any ethical system.  Hey, if you raise everyone as Kantians and teach them to see the moral truth in Kantianism, chances are, the majority will think the categorical imperative (one should only act according to principles that you'd want everyone to act on) is the one true moral principle.

Actually, if you ax most 'mericans (Republicans, anyway) they'll probably advocate an egoist morality; that is, since people are rational and self-interested, actions that are in line with the principle of rational self-interest are 'right'--provided another's rights aren't infringed upon.   If only they knew they are really just misguided utilitarians...

Anyhow, what really jumps out at me is how Aristotelian Mill sounds wilt all this moral education stuff.  Aristotle basically said (super condensed version), an action is good if it is by a virtuous person and a virtuous person is one who has had a correct moral education.  In a way, Mills just adding on that someone with the correct moral education would act according to the utilitarian principle.

Sanctions
Recall that the whole point of this section of the utilitarian argument is to defend utilitarianism from critics who charge that utilitarianism can't work because there's no reason for people to go along with it.  In this context, Mill discusses external and internal sanctions that may or may not compel someone to act according to the utilitarian ethic.  Regarding external sanctions he says they are the same for any possible moral system: desire to be praised and avoid punishment (earthly or cosmic).  Lets move on to internal sanctions...

Internal SanctionsSo, what is it that might compel us to consider our action's effect on the general good above all other considerations?   What is it that makes us feel as though we have a duty to consider the general good? It is "a feeling in the mind; a pain, more or less intense, attendant on violation of duty, which in properly cultivated moral natures rises, in the more serious cases, into shrinking from its impossibility."  In other words, our conscience.

Lets call it a special feeling; lets call the feeling of moral duty "the essence of conscience".  There we have it--the thing that compels us to act according to utilitarian ethic is our conscience.  Admittedly, we rarely feel pure duty because we often have competing feelings, interests, and social conditioning running around in our heads that distort this sense of moral duty.

But how does pure conscience bind us to a particular course of action (i.e., the 1st principle of utilitarianism)?  It binds us because it is "a mass of feeling which must be broken through in order to do what violates our standard of right, and which if we do nevertheless violate that standard, will probably have to be encountered afterwards in the form of remorse."  In other words, our conscience binds us because we cannot escape it.

The obvious objection is that there are people who don't have strong feelings of conscience or are able to ignore their conscience, so how can we say that utilitarianism binds people to action?  Mill's (reoccurring) reply is that this is a problem for any ethical system--it is not particular to utilitarianism.  Such people can only be compelled to act through external sanctions regardless of what moral system you support.   So, I guess this is meant to diffuse the argument that utilitarian ethics should be rejected because it can't bind people to follow it, but neither is it a point in favour of utilitarianism.

On the Origins of the Feeling of Duty
Mill begins that the origins of the feelings of duty, be they innate or acquired, are unimportant because the net result is the same.  Supposing they are innate (here he's implying Kantian ethics), then the feeling of duty would attach to moral principles.  But there is no argument to suggest that the innate feeling of duty wouldn't attach to the utilitarian principle rather then, lets say, the categorical imperative.  Furthermore, if morality itself is intuitive, it seems that accounting for the effect of our actions on the happiness of others is "intuitively obligatory".  So, even if our sense of moral duty is innate (which Mill denies) this is no objection to utilitarianism.

Suppose instead, as Mill does, that moral feelings are learned rather than innate.  They are something we (hopefully) develop over time with experience and education just as we do with things like the ability to reason, to use language, to play an instrument... Just like any capacity we have, our moral feelings can develop to varying degrees, both positively and negatively.  So, even if our moral conscience is acquired rather than innate, there is no reason to suppose it couldn't develop to follow utilitarian principles (amongst all the other possibilities).

Then Why Utilitarianism? Finally we learn why our conscience will be receptive to utilitarian principles rather than others.  Given that, regardless of the origins of our sense of duty and moral conscience, what arguments are there to suppose the utilitarian ethics is the one true standard?  So far we've said that human can be conditioned to attach a sense of moral duty to just about moral principle.

Ah! Ha!  But you see, the utilitarian principle is special! The is a "powerful natural basis of sentiment for utilitarian morality".  You see, once the general happiness is recognized as the ethical standard it will be the basis of this powerful natural sentiment.  And that natural oh-so-good feeling is the social feeling of mankind--"the desire to be in unity with our fellow creatures..."; that is, our natural tendency to live as social creatures.  It is unnatural for us to live outside of a social context.

It's hard to dispute that we are social creatures but some people might reply that our natural tendency toward social living doesn't necessarily entail utilitarianism.  An egoist or social contract theorist might say, for example, that social living just means that I have to abide by certain conventions if I want to get out of life what I want but still avoid (external) sanctions.

Mill further argues that social living is impossible unless the members regard everyone's interests to be equal.  People grow up with the understanding that they have to include the interests of others when/before they act.  They learn not to injure others.  In instances of cooperation they learn that interests can be mutual and that our own well being is often bound up in that of others.  He goes on to paint a very pretty picture:

Not only does all strengthening of social ties, and all healthy growth of society, give to each individual a stronger personal interest in practically consulting the welfare of others, it also leads him to identify his feelings more and more with their good, or at least with an even greater degree of practical consideration for it.

Under these conditions he will, as a matter of habit, consider the good of others in his actions.  Once he has this feeling he will want to demonstrate it, and encourage it in others.  And even if he doesn't have utilitarian sentiments, for his own self-interest he will want others to be utilitarians because he will benefit.  Before long and by this process the utilitarian meme takes over the society, removing sources of opposition and "leveling those inequalities of legal privilege between individuals or classes".

Here's the really interesting thing.  In a way Mill was right.  Empirical evidence suggests that most people think like utilitarians (however, it varies between cultures and contexts).  Also, that in groups where there are strong social ties members do tend to consider the happiness of the other members in their moral calculus.  As the intellectual underpinnings and the utilitarian feelings of the individual grow, he will oppose socio-economic and socio-political structures that prevent others from having the benefits he has.  Through this mechanism the moral community grows in number.

Basically, once you go utilitarian you never go back cuz it just feels sooooo natural.  When you accept utilitarianism into your heart it is not as "a law despotically imposed by the power of society, but as an attribute which is would not be well for them to be without".  Utilitarianism, once embraced, works in harmony with external or internal motives to care for others.  When external sanctions fail to motivate, the utilitarian ethic will provide internal motivation (sense of duty) to consider the happiness of others (in proportion to the extent to which to agent is utilitarian).

Sounds nice, doesn't it?