Monday, April 07, 2008

Faithing all the way

When I asked a Christian friend how her church defined faith, she directed me to the bible, specifically to Hebrews 11:1. Her text follows the KJV: "Now faith is the substance of things hoped for, the evidence of things not seen." Since I flunked Shakespeare, I asked her what "substance" in this context means and what "evidence" was being alluded to. Well, she was as stumped as I was. So I hunted down other translations in the hope of finding something in modern colloquial English. Here are the various renditions (site 1, site 2) I found:
Now faith is the substance of things hoped for, and the sign that the things not seen are true.

Now faith is the assurance of things hoped for, the conviction of things not seen.

Faith assures us of things we expect and convinces us of the existence of things we cannot see.

Faith is a sure confidence of things which are hoped for, and a certainty of things which are not seen.

Now faith is a well-grounded assurance of that for which we hope, and a conviction of the reality of things which we do not see.

And faith is of things hoped for a confidence, of matters not seen a conviction,

Now faith is being sure of what we hope for, being convinced of what we do not see.

Now faith is being sure of what we hope for and certain of what we do not see.

What is faith? It is the confident assurance that what we hope for is going to happen. It is the evidence of things we cannot yet see.

The fundamental fact of existence is that this trust in God, this faith, is the firm foundation under everything that makes life worth living. It's our handle on what we can't see.

I think the key words are assurance, being sure, confidence, conviction, certainty. If this is what faith is in the biblical sense--being sure of receiving/attaining things that one hopes for, being sure of the reality of things one does not and cannot see (perceive)--then it is quite synonymous with how we usually understand "faith," i.e., a firm belief without evidence or strong belief despite the lack of evidence.

Immediately, however, as with believing in any other thing Hebrews 11:1 runs afoul of epistemology. However sure, confident, and certain we are that what we hope for and what we cannot see is true, our fervent belief tells us nothing about whether in fact we are right or wrong, whether or not what we believe in is true/real. For example, there are adherents of every religion who are die-hard believers. But since many claims of the various religions of the world conflict with one another and therefore cannot be true simultaneously, then clearly faith (belief) does not lead to (an apprehension of) the truth. Surety, confidence, certainty are just that. They do not imply that what is believed in is true, much less make it true.

Given that they planned and trained for years with the ultimate goal of sacrificing their lives, the 9-11 terrorists must be counted among those who had the most faith in their beliefs. However, it's rather comical to conclude that simply because these hijackers firmly believed their deity would reward them with six dozen virgins each for their murderous deeds, they in fact are now wallowing in a sea of young females in some dimension.

So faith is irrelevant to the truth of the belief. But Christians believe in Hebrews 11:1. And some believe in it with all their hearts. But as we have already said believing will not suddenly make that which is believed in true. Merely believing in Hebrews 11:1 or being certain (having faith) that the claim therein is true does not tell us anything about the truth of that passage. The pertinent question for Christians therefore is: Why do you believe that verse? Why do you believe the claims therein? What makes you sure that it is true? Queried, they will almost surely whip out some lame reason (e.g. "because it's in the bible," "because it's God's word") which does not at all justify the belief, or which contains implicit premises that have not been substantiated and known to be true, or which ultimately ends up begging the question (circular reasoning).

I am led to hypothesize that believers are not truth seekers at all. "The truth will set you free" is paid lip service. Instead believers are in the business of taking as truth that which they want to be true and that which they hope for (remember, they cherry pick) regardless of whether or not these beliefs are rooted in reality, plausibility, and rationality. In effect they unconsciously tell themselves: "I like the idea of an afterlife, of spending an eternity with my loved ones, therefore I will hold this belief despite and regardless of ...." "I feel solace and comfort in the idea of a benevolent deity who hears and answers prayers therefore I will continue to believe in it despite and regardless of ...." Preference trumps evidence and rationality. And there's an obstinacy and hard-headedness to it that appropriately deserves the epithet "blind faith." Believers seem to be declaring: I believe this to be true and real whether or not it is true and real.

Faithing in contrast to thinking seems to be prime mover amongst Christians. As the Apostle's creed epitomizes there's an emphasis on believing. Believe and you will be saved. Believe and you will be healed. Just believe. And when Christians run into disconfirming evidence and cognitive dissonance, they just go over the bumps, forget about it in no time, and move on, their belief engine chugging along as if nothing had happened.

It seems to me in order to arrest this runaway train takes a mountain of cognitive dissonance, something their faith can't move or go over or around. But what will actually break the spell (not exactly as Dan Dennett used the phrase) is idiosyncratic for every believer, as stories of deconversion show.

Saturday, April 05, 2008

Cherry-picking Cathy the Catholic

The number of variants among believers was brought home to me recently when I confronted Cathy of Touched by a Miracle about my comments on her blog which she deleted, comments which don't contain ad hominems but instead well-reasoned arguments and explanations (see below for the comments I left in her blog, as well as her replies; you be the judge). Apparently, two Catholics may not at all believe in the same thing, leaving us with a number of variants of the Catholic species. And as you will shortly see John Paul 2 and Cathy's beliefs are hardly congruous. Given what the successor of Jesus declares I wonder if heresy would be too strong a word to describe Cathy's obstinacy.

After I discovered the deletions, I wrote Cathy and asked her for her reasons. Since I've suspected that this postgraduate degree holder had poor critical thinking skills and would probably be averse to penetrating analysis (perhaps fearing it would burst her bubble of delusion or those of her readers) I told her that in his encyclical Fides et ratio Pope John Paul 2 declares that faith and reason do not clash but rather complement one another. In fact according to the pope,
It is an illusion to think that faith, tied to weak reasoning, might be more penetrating; on the contrary, faith then runs the grave risk of withering into myth or superstition.

I told her that as a Catholic I thought she would know better than to censor rationality. Well I never received a reply. Instead I discovered she's appended the following to her "About this blog."
This is my sanctuary and not a forum to argue about faith. I respect other people's faith and religion for I believe God is the God of the Universe. Please respect mine. If you have issues about religion, you can write about it in your blog.

The above reminds me of psychiatrist M. Scott Peck's observation in his visits to asylums. Peck relates how when he called the inmates' attention to the first snow of winter, they in effect told him: Don't bother us, don't interrupt our delusions. It looks like Cathy wants me and her Pope not only to not interrupt her delusions, but to respect them.

Poor Cathy. She won't even acknowledge that her god is not the god of other religions (and not even the god of some Christian denominations and sects). And that if she respects the beliefs of those religions then she is subscribing to a form of subjectivism. I really have to wonder if "truth" has any currency in her worldview at all. It almost seems like her religion is just a "feel good" thing bereft of any substantive thinking or intellectual consistency.

Hence, while Cathy may call herself a Catholic, she cherry picks what Catholic doctrines she will believe in, what she will espouse, and what she will listen to. Even as the Vicar of Christ himself has told her to value rationality, she summarily rejects this. Thus, as predicted by John Paul 2, she has pitifully slid into superstitious beliefs.


What seems to have prompted Cathy to take down my comments (and her replies to the same) is the fact that after disappearing for a week I sent another comment. Perhaps there was something in there that ticked her off. I'd like to think that sometimes the light of reason can bring people to lash out at that which threatens to pull the rug from under them. Or perhaps she had already told herself that if I ever post a third comment she'd strafe all my posts to kingdom come. Or perhaps Easter Sunday marks the beginning of her spring cleaning, and she was just nonchalantly taking out the garbage--meaning any comment that dare invoke skepticism, logic, rationality, and critical thinking. Seriously though, it now seems clear that it was my last submission that got her goat. Given that she now says her blog is not a venue for debating faith, my excursus on the nature of faith must've made her go into conniptions and triggered the deletion frenzy. What follows are the comments Cathy fed to the delete button.

By me on March 15 in "How do you know if your prayers are answered?":
There's a fallacy in causal reasoning known as post hoc ergo propter hoc ("after this, therefore because of this"). Given that event A comes before event B, it is fallacious to conclude that A caused B. We all intuitively know that mere temporal precedence is insufficient to conclude causality. Thus, just because I sang right before a downpour doesn't mean that my singing really sucks so much so that the clouds uncontrollably burst into tears.

Applying this to prayer it means that if I pray to entity Z and shortly thereafter I receive what I prayed for, I cannot say whether or not I got what wanted because I prayed. If I pray that I won't meet an accident during my trip and in fact I arrive safely at my destination, I would have to have knowledge that I would've had a mishap had I forgone with the prayer. Only then can I say that prayer was in fact essential and causative. Of course neither I nor anyone else has the luxury of knowing the consequences of "what if I hadn't prayed."

Thus, we cannot say whether prayers are answered simply because what we want or wish came to pass.

As for prayers not being answered, this is more straightforward. Given my above prayer, should the plane or car I'm in figure in a crash, then I can conclude that my prayer did not work. Of course there are an infinite number of explanations that can be offered to rationalize this away. For instance I can say that Z was too busy attending to prayers by other people. Or that Z wanted to teach me a lesson and so allowed me to get nicked. Etc. These, however, are all ad hoc explanations whose truth/falsity cannot be determined, cannot be tested. They are mere speculations to explain away the negative outcome.

By Cathy on March 17 in the same blog entry:
As always, faith defies logic.

There would be no word miracle if everything can be explained by science.

By Cathy on March 17 in the same blog entry:
As Albert Einstein had said:

The most beautiful thing we can experience is the mysterious. It is the source of all true art and science.

By me on March 17 in "Let there be a miracle":
According to the most rigorous study thus far conducted, intercessory prayer has no measurable empirical effects. Dr. Herbert Benson et al. conducted the Study on the Therapeutic Effects of Intercessory Prayer (STEP). To date it's considered the definitive scientific study/experiment on prayer. It involved 1,800 patients in 6 different hospitals who were recovering from heart bypass surgery. The study and its results appear in the April 2006 issue of the American Heart Journal. To cut to the chase, they found that there was no difference in the rates of recovery and improvements between those prayed for and those who weren't; there was also no statistical difference in the number of deaths between the two groups. In short, prayer did not work. There was, however, an interesting side discovery. The researchers found that those who knew they were being prayed for suffered more post-operative complications. The difference was small but statistically significant. So knowing that one is being prayed for could be hazardous to one's health, which according to one hypothesis may be due to some type of performance anxiety. Intercessory prayer has all but been proved to have no efficacy.

It may be claimed that Fernando Suarez is no ordinary mortal, that he has certain paranormal/supernatural abilities, or that he has a hotline to the Judeo-Xian deity. Thus, unlike the participants in STEP, Suarez may in fact have powers to heal through prayer. This hypothesis can in principle be tested. Here's a rough sketch of how we may test the healing claims. Patients are first diagnosed by medical experts to determine their condition (appropriate lab tests should be performed as well). Medication and various other treatments these patients have been receiving should be terminated in order not to confound the study. This is probably unethical but for now let's disregard bioethical issues for the sake of illustration purposes. After the effects of previous medication/treatments have worn off, Suarez then prays for these people (or performs whatever it is he does). Thereafter, the patients are once more diagnosed and tested. Daily/weekly/monthly medical follow-ups and tests are then conducted to monitor and track the progress/regress of the patients condition. Should we find improvement that cannot be attributed to the medications/treatments that the patients had undergone previously, to the natural course of the disease and the expected variability of severity of its symptoms, to natural regression and remission, to placebo effects, to misdiagnoses, and to any host of known causes/explanations, then we can tentatively say that such improvements may be due to Suarez's healing techniques. We can then perform further studies. On the other hand if we find the patients regress or even die from their conditions then we have falsified Suarez's healing claims. (The latter was in fact the case with healer Benny Hinn after an investigation was conducted. See

I've posted more detailed critiques of the claims surrounding Suarez over at While anecdotes may seem to evince the efficacy of faith healing, it is only via objective testing, studies, and long term medical investigations can we arrive at a determination of the efficacy of any treatment modality.

I posted the following on March 25 in "How do you know if your prayers are answered?" but Cathy never approved it. Shortly after submitting it Cathy took down the two comments I left on her blog:
I'm not sure what you mean by "faith defies logic." But allow me to say some things about faith.

* St. Thomas Aquinas said that faith is inferior to knowledge because it lacks rational justification. Faith, precisely, is belief despite the lack of justification/substantiation/evidence. When we do have good reasons/arguments/evidence to justify our belief, we call it knowledge.

* No matter how much we believe in X our belief cannot make X true (or false). Even if a trillion people believe in X it will not make X true (or false). No matter how long X has been believed it will not make it true (or false). Example: Members of the Heaven's Gate cult very much believed their salvation was at hand in 1997 when Comet Hale-Bopp came within naked eye view. The cult members had so much faith that they went as far as committing suicide in order to board the extraterrestrial ship they believed had come for them. Clearly, even if Heaven's Gate had a trillion members and had been the earliest human religion ever, it would not have made their beliefs in the Hale-Bopp extraterrestrial spaceship true.

* All religions have their staunch believers. Since all religions rely on faith (none of them have any good justification/evidence for any of their theological claims), we are left with a major conundrum if we claim that faith leads to truth: It would mean all the claims, including all the gods of all religions are true/real. That would of course be a contradiction since the beliefs of a lot if not most religions conflict with one another and cannot be simultaneously true. For instance, if the Hindu gods are real then neither the Islamic nor the Xian deity nor gods of a good number of other religions can be real. Thus, merely having faith does not lead to the truth.

* Since religions cannot all be simultaneously true, then it follows that most religious beliefs are false--regardless of how many believe in them, how long they've been believed in, and however much faith has been invested in them. Faith isn't correlated with truth. In fact it is irrelevant to the issue of truth.

You said, "There would be no word miracle if everything can be explained by science." I think you're alluding to the God of the gaps argument (GOPA). In simple terms the GOPA goes as follows: there is currently no scientific explanation for X, therefore X is supernatural or supernaturally caused. The problem with GOPA is that over the centuries things that used to be thought of as being caused by gods are now known to have naturalistic causes. Lightning, earthquakes, disease, eclipses, etc. used to be imbued with so much supernatural overlays. But every high school student now learns about their true nature and causes in science class. So what is currently unknown--what Einstein dubs the mysterious--will most likely be understood and known in the future. What the Einsteins of today don't understand--but are intensely motivated to study--will become common place knowledge to the high school students generations hence. Thus, to call the unkonwns of today "miracles" is in fact simply admitting ignorance of their real nature and cause. But as we've learned from history if we don't know X and call it a miracle we (or most probably our descendants) will almost surely find ourselves wrong.

In logic and epistemology, when we don't know what X is, we cannot conclude that X is Y, where Y is our pet theory (e.g. Y = "a miracle", or Y = "extraterrestrially caused," or Y = "due to psychic powers", etc.) Precisely, we don't know what X is and so the only thing we can say is that we are ignorant of X, of its nature, of its cause. To say that X is Y is to implicitly claim knowledge of X, which of course is arrogance and implies we have omniscience (since we are claiming that X cannot be anything else other than Y, meaning we have ruled out any and all other possible explanations, now or in the future).

Moreover, if we were to say that X is a miracle, then it behooves us to produce evidence that our claim is true. One cannot point to the lack of scientific explanation since that doesn't prove anything. As we said the current lack of scientific understanding/explanation merely means that humans still don't have knowledge of what X is. Furthermore, the burden of proof is always upon the one making the claim. Thus, if I say that X is not a miracle but rather caused by a super-advanced super-intelligent race of extraterrestrials, then the onus of proof is upon my shoulders to produce evidence for what I have claimed. If I cannot then I am merely speculating and my (wacky) claim can be dismissed. Worse I have made a nonparsimonious claim, ie., a claim that assumes the existence of entities that are not known to be true (in this case aliens).

And so vis-a-vis the claim that "X is a miracle":
1. It is a claim that isn't warranted by humanity's current state of ignorance of what X is.
2. to insist that X is a miracle is to imply omniscience (which is hybristic)
3. burden of proof is upon those who claim miracles; they need to produce persuasive evidence
4. the assumption of deities and the supernatural violates the principle of parsimony, more commonly known as Ockham's Razor, first annunciated by the Catholic monk William of Ockham in the 14th century

Friday, April 04, 2008

Does Suraez have a FPP?

Some 25 years ago psychologists Sheryl Wilson and Theodore Barber identified what they called fantasy-prone personality (FPP). The 14 characteristics of FPP are:
(1) being an excellent hypnotic subject, (2) having imaginary playmates as a child, (3) fantasizing frequently as a child, (4) adopting a fantasy identity, (5) experiencing imagined sensations as real, (6) having vivid sensory perceptions, (7) reliving past experiences, (8) claiming psychic powers, (9) having out-of-body or floating experiences, (10) receiving poems, messages, etc., from spirits, higher intelligences, and the like, (11) being involved in "healing," (12) encountering apparitions, (13) experiencing hypnagogic hallucinations (waking dreams), and (14) seeing classical hypnagogic imagery (such as spirits or monsters from outer space).

According to Wilson and Barber a minimum of six of the above "diagnostic criteria" (if we may call it that) would indicate FPP. We all have the faculty for fantasizing and we all have had fantasies so all of us would have a couple of the characteristics above. In my case #3 definitely applies. But I have no idea of my hypnotizability. I don't remember having had imaginary friends as a child nor having adopted a fantasy identity (although am not sure exactly what that means). I may have on occasion imagined sensations as being very real. On the other hand, How vivid is "vivid sensory perceptions"? An operational definition is necessary. What does "reliving past experiences" mean exactly? As to #8 to 14 I am confident they do not apply to me. Bottom line--I check positive for at least two items while the worst case scenario is that I'm a point shy of the half dozen mark.

Let's see how Suarez fares. Suarez claims to have seen apparitions of the Virgin Mary, who also gave him a message: "She told me that I would go to a far away place which was cold and windy, and there proclaim the word of God." In a tv interview (with Boy Abunda) he's admitted to having encountered the devil (I need a reconfirmation on this). Suarez has also had a vision of Jesus "pouring on graces upon him." And, needless to say, he's very much involved in healing. Given these we can safely tick numbers 10, 11, and 12. Because we lack a book-length biography on Suarez, I'm most interested in how he will rate himself on the other items (except perhaps for #1 which would require an actual test by a qualified hypnotist).

It's been suggested that faith healers Kathryn Kuhlman and Benny Hinn have FPP given that their backgrounds show they have many FPP traits. It would thus not be surprising if we find Suarez to be of the same feather. However, I doubt we can settle Suarez's fantasy proneness if we rely merely on Suarez, for I surely am doubtful he would willingly provide the pertinent and necessary information about himself [1]. Too much is at stake. He and his cohorts have invested too much psychologically and in time and effort. Suarez has hundreds of thousands if not millions of followers. He's in too deep. Interviewing relatives, friends, schoolmates, teachers, colleagues, the seminaries that rejected him may be more revealing.



1. Ever since I read about Suarez's past I've been skeptical. For instance he says that at age 16 he prayed over a paralyzed woman and the woman got up and walked. And about a decade ago he prayed over a dead woman who then came back to life. I take these anecdotes with more than just a grain of salt since memory is very much reconstructive in nature--it is nothing close to a videotape that faithfully records events. I am thus very wary of confabulations and embellishments that may have crept in. So much more if Suarez is in fact fantasy-prone. While I don't believe Suarez to be a fraud who's made up all these stories, I certainly would want solid evidence for what actually took place when he was 16 and with the resurrectee. Given these, even if Suarez were to be very open and tell us whatever we wanted to know, I'd be most cautious in taking his answers at face value.

Tuesday, April 01, 2008

Believers are unbiased and objective

While in a car on a 10-minute ride with, among others, a pastor and his wife, the conversation turned to health and disease. The pastor's spouse (who turned out to be far more voluble than her preacher husband) spoke of the power of prayer and advised the person I was with to pray to God and Jesus to address her various chronic conditions. To show just how powerful and effective entreaties to the Lord are, she related the story of a 60-year old female member of their congregation who had been diagnosed with stage 3 cancer. Through prayer she completely recovered. It's been five years now and this elderly lady has regained the weight she lost and is in the pink again. Here's where it gets interesting. Without being prompted or asked she nonchalantly added that this woman had undergone chemotherapy and that the prayers helped her endure its nasty side effects. Given the circumstances a confrontation was totally out of the question and so I merely chuckled to myself.

After years of having been exposed to the mindset and the reasoning of those who believe in prayer and faith healing, I'm beginning to see that these people are prone to confirmation bias in some of the most egregious ways possible. Suppose that a patient had undergone a set of medical interventions. Let's say that prayers/faith healing rituals (let's call that P) are then also thrown in for good measure. If it turns out that the patient gets well, believers will attribute efficacy to P. They will thank God and praise the Lord. Interestingly, however, even if P is not initiated, you still have believers chalking up the positive outcome to their invisible leader, but oddly enough not attributing it to the work and effort over the years and decades of the hundreds and thousands of men and women who've contributed to the development and implementation of the diagnostic procedures, instruments, equipment, pharmaceuticals and treatments that were employed. (After undergoing emergency surgery in 2006 philosopher Daniel Dennett delves into this in "Thank Goodness!")

Were we to confront the pastor and his wife with the question, "If the 60-year old woman had not resorted to any medical treatment whatsoever, do you think that prayers alone would have licked her cancer?" I believe they'd hesitate. I doubt they'd glibly say, "Oh yes, without a doubt." I imagine they'd say something like, "God works through doctors." It almost seems to me that for most believers such as the preacher and his spouse it is an accepted fact that science and medicine are part and parcel of health and healing. What they do and have done is to hitch prayer onto the proven efficacy and track record of medicine (and then blissfully and blatantly commit the non causa pro causa fallacy). I'll hazard a guess that for most believers prayers are not there to replace doctors and drugs but rather they're there in the belief that they will assist, promote, or even ensure the effectiveness of the medical treatments. I wonder if it ever enters their mind that P may be superfluous, that the surgery, pharmaceuticals, chemotherapy, etc. may be sufficient, or in the case when even the best of medical technology is ineffective or futile or too late, that the absence/presence of prayers is irrelevant. So how does the pastor know prayers had anything to do with the recovery of his female congregant? What of his other church members who had cancer, were prayed for, but who got worse or died? What does or would that say about the power of prayer?

During services and bible meetings, when members share their testimonies you don't hear them tell such stories as, "I prayed to the Lord. Everyday, for two months, my family and friends all prayed with me. But the Lord did not save my son." With such a story how in heavens' name will the minister and the fellow members utter the mandatory twice-a-minute refrain "Praise the Lord!"? What you do hear are stories that ostensibly confirm the efficacy of prayer, the goodness and trustworthiness of their deity, and other things they believe in. If you do hear a downer as the one above, it will surely be followed by something that will end the testimony on a bright note, even if it's just the hope that things will turn out for the better. And on the off chance that the person testifying doesn't provide it, his peers will. In the world of religion, disconfirming evidence is a (mind) virus that triggers the immune response and is dealt with immediately at all costs.

The end result of exposure to predominantly positive stories, to spins on even negative outcomes of prayer/faith, is confirmation bias. Believers tend to see prayer and faith in a very positive light: Prayer does work and if it apparently doesn't then one's continuing faith is called for, for God's ways are mysterious and he knows best.

You may initially have thought that the title of this blog entry had a typo. But the declarative is there to prod you to supply a question mark. Try asking Christians the questions below. You can wait for their reply to each before asking the next, or you can just fire all questions at once. (It's my guess that the two approaches will elicit quite different responses to question #1.)

1. Are believers unbiased and objective evaluators of the effectiveness of prayer and faith healing?
2. What do you think are the means by which an unbiased and objective assessment can be made?
3. How do you know these means are unbiased and objective?

Using the second method of questioning I asked a Christian friend the first two items. To the first she replied that believers are probably not unbiased and objective, that those who are not fully into religion may be more objective. To the second question she candidly admits she doesn't know what such means would be. I'm of course wondering how she would've replied to #1 had I withheld #2. Would she have been less thoughtful/careful and answered yes?

Question #2 makes the person examine what he takes to be the means by which prayer and faith healing are efficacious. Are they objective and unbiased? #2 can't be answered with a yes or no. It involves thinking and elucidation. It's a question that's bound to give Christians pause. Hopefully the mental rigor, inspection and even introspection involved would lead to the realization that objective evaluation (which is taken to be good in contrast to a biased assessment) is more than just believing and that it isn't some facile, illogical method as with what the preacher and his wife employed.

If #2 was a toughie, then question #3 is a reinforced concrete wall. This is the end of the line for most believers. Stumped, some of them will switch to irrational mode and will let anger end the line of inquiry.

There are those who will contend that there is no objective way to test the efficacy of prayer. Such a claim sounds eerily like that of previous Chair of the Society of Homeopaths Felicity Lee. In her special pleading she claims placebo-controlled RCTs aren't suited to testing homeopathy's effectiveness. Questioned as to why this is, Lee had no answer. So how does she and her fellow practitioners know that homeopathy works? Case studies. In other words, anecdotes by homeopaths. Bottom line is that for alt. med including faith healing the only "evidence" is subjective in nature.