Monday, 21 July 2014

Ancel B. Keys' critique of "Diet and coronary thrombosis. Hypothesis and fact, by John Yudkin. The Lancet, 1957."

Ancel B. Keys has come in for a lot of flak recently over alleged "cherry-picking" of data for his 6/7 Countries studies. Here's Keys' critique:- "SUCROSE IN THE DIET AND CORONARY HEART DISEASE" of Dr. John Yudkin's "15 Countries" article.

Keys accuses Yudkin of bias, cherry-picking countries that fit his own hypothesis. The irony.

Here are some plots from Keys' 11 Countries article.
5-Year CHD cases/1,000 men vs Sucrose %E.

5-Year CHD cases/1,000 men vs Sat Fats %E.

Sucrose %E vs Sat Fats %E.

So there you have it.

Saturday, 19 July 2014

Diet and coronary thrombosis. Hypothesis and fact, by John Yudkin. The Lancet, 1957.

Twitter did it again. From http://www.abc.net.au/catalyst/heartofthematter/download/Yudkinssugartheory.pdf
This looks like bad news for the fat-lovers.

There's an association between total fat intake and Coronary mortality rate. At high total fat intakes, there's a large variation in Coronary mortality rate, suggesting that other factors are becoming significant.

This looks like bad news for the meat/fowl/fish/cheese/egg-lovers.


This looks like bad news for the sugar-lovers.

Of course, correlation ≠ causation.
This looks like bad news for rich people.

In conclusion, total fat intake, animal protein intake, sugar intake & annual income are all associated with increased Coronary mortality.

Thursday, 17 July 2014

Why do some people have trouble doing things in moderation?

This is related to my previous post.
From http://www.kindredcommunity.com/2013/01/xtreme-eating-awards-2013-extremism-running-amok-at-americas-restaurant-chains/

Some people take low-carbing to an extreme, 'cos if reducing carbohydrate intake has benefits, reducing it to zero must be better. Oy!


We're told that eating 5 portions of fruit and vegetables a day is good for us. One patient who was admitted to St George's with malnutrition, had been eating more than 50 portions of fruit and vegetables a day, 'cos if 5 portions of fruit and vegetables a day is good for us, 50 portions of fruit and vegetables a day must be better. Oy!


People who are taking the anti-clotting medication Warfarin need to maintain an accurate balance between their warfarin dose and their Vitamin K intake to keep their INR between 2 and 3, as warfarin antagonizes vitamin K1 recycling, depleting active vitamin K1.
"Between 2003 and 2004, the UK Committee on Safety of Medicines received several reports of increased INR and risk of haemorrhage in people taking warfarin and cranberry juice. Data establishing a causal relationship is still lacking, and a 2006 review found no cases of this interaction reported to the FDA; nevertheless, several authors have recommended that both doctors and patients be made aware of its possibility. The mechanism behind the interaction is still unclear." Here's a clue...

From Possible interaction between warfarin and cranberry juice (emphasis, mine):-
"After a chest infection (treated with cefalexin), a man in his 70s had a poor appetite for two weeks and ate next to nothing, taking only cranberry juice as well as his regular drugs (digoxin, phenytoin, and Warfarin). Six weeks after starting cranberry juice he had been admitted to hospital with an INR (international normalised ratio) > 50. Before, his control of INR had been stable. He died of a gastrointestinal and pericardial haemorrhage. He had not taken any over the counter preparations or herbal medicines, and he had been taking his drugs correctly." Cranberry juice contains no Vitamin K. Oy!

"The Committee on Safety of Medicines has received seven other reports through the yellow card reporting scheme about a possible interaction between warfarin and cranberry juice leading to changes in INR or bleeding. In four cases, the increase in INR or bleeding after patients had drunk cranberry juice was less dramatic. In two cases, INR was generally unstable, and in another case INR decreased. Limited information is available about whether patients complied with their treatment in these cases.

Cranberry juice (Vaccinium macrocarpon) is popular and is also used to prevent cystitis. Interaction with warfarin is biologically plausible, because cranberry juice contains antioxidants, including flavonoids, which are known to inhibit cytochrome P450 enzymes, and warfarin is predominantly metabolised by P450 CYP2C9. The constituents of different brands of cranberry juice may vary, and this might affect their potential for interacting with drugs. Whether the constituents of cranberry juice inhibit CYP2C9 and therefore the metabolism of warfarin or interact in another way needs further investigation. Until then, patients taking warfarin would be prudent to limit their intake of this drink." Oy!

So, one man's inadvertent (his doctor should have warned him about eating next to nothing while taking warfarin) dietary extremism resulted in his own death and the restricted intake of cranberry juice for everybody else taking warfarin. Oy. :-(


P.S. It's about time an alternative to warfarin was found. It's difficult to maintain an accurate balance between warfarin dose and Vitamin K intake.

Wednesday, 16 July 2014

Jumping through hoops, and my Blog List.

I'm seeing a curious thing. The VLC "camp" seems to be "jumping through hoops" to prove a point.
From http://davidbressler.com/2013/08/26/easier-harder/

From Neuron fuel and function (emphasis & formatting, mine):-
"Ketones and lactate do not drive reverse electron flow through complex I. Glucose can. Palmitate certainly can. What you want from a metabolic fuel depends on the remit of your cell types. Neurons within the brain preserve information by their continued existence.

This is best done by burning lactate or ketones. NOT glucose and, of course, not FFAs.

Anyone who claims that glucose is the preferred metabolic fuel of the brain has not though (sic) about what a neuron has to do and what an astrocyte actually does do. Or much about the electron transport chain."

Basically, glucose is bad mmm-kay. Also, anyone who claims that glucose is the preferred metabolic fuel of the brain is a dumb-ass. Damn our livers & kidneys churning out glucose! Are they trying to kill us?

∴ Carbohydrates are bad and must be avoided at all cost! This, of course, is utter nonsense.

Glucose can drive reverse electron flow through complex I. Can means that it's possible. Is it probable?

On a hypercaloric Western diet of excessive crap-in-a-bag/box/bottle, yes.

On a Kitavan diet of ~70%E from tubers, no.

On a diet of Basmati rice & beans, no.

On a diet of whole fruits, no.

See also Another crash and burn on low carb paleo and CrossFit. Enough of the 'carbs are evil' nonsense. Carbphobia is hurting a lot of people.

I have a list of blogs that I read on a regular basis. As a result of the bad science & cherry-picking displayed in various VLC blogs, I have deleted them from my Blog List.

See also Guest post: Denialism as Pseudoscientific Thinking.

Sunday, 13 July 2014

The "I'm a Celebrity... Get Me Out of Here! (losing team)" diet.

This post may be a little "tongue-in-cheek", in places.


I nearly used a certain scene from Blazing Saddles. It would have been much more entertaining.

As I said in Why you really can't outrun your fork:-
"Although I totally support the use of low-carbohydrate/calorie diets for people with Insulin Resistance or Type 2 diabetes, now that I'm no longer insulin resistant, I can eat natural carbohydrates without any problems.

A medium-sized (orange-fleshed) Sweet Potato takes only 4 minutes to bake in its jacket in a 700W microwave oven. The flesh is moist & sweet, unlike that of a Yam or potato.

I eat the whole thing, including the jacket. It's very filling and I'm still able to lose weight. For active and Insulin Sensitive people, a Kitavan-style diet is absolutely fine."

In the TV series "I'm a Celebrity... Get Me Out of Here!", there are two teams at the beginning. Members of each team compete against each other, to win food for their respective teams. The winning team gets to eat all sorts of exciting animal produce from "down-under". The losing team gets to eat rice & beans.

By the end of the series, team members (especially the over-fat celebrities) had lost a lot of body-fat. Coincidence? I think not. Combining Long-grain Rice with Beans (set Serving size: to 100g) provides all the Essential Amino Acids and is very filling. How do I know this? Guess!

I never used to like rice (it was always cooked "a l'anglaise"), but adding a squirt of Sweet Chilli Sauce to Basmati rice before cooking, makes it taste good.

Friday, 11 July 2014

Nutritional Ketosis: What is it good for?

I have a video in mind...


Having previously shown you what I look like on a lowish-carbohydrate diet, here are a couple of recent pictures of Jimmy Moore, who's on a very-low-carb, very-high-fat diet (~85%E from fats), a.k.a. Nutritional Ketosis. It involves adding Kerrygold butter to just about everything, even eating sticks of it from a block. I'm not kidding.
I told you I wasn't kidding.

From Google Image Search on "Jimmy Moore" OR "Livin la Vida low carb", images in the last 7 days:-
On 6.7.14.

On 8.7.14.

The only recent footage of Fredrick Hahn, is the following video from the Low Carb Cruise...


To my eyes, Nutritional Ketosis is good for absolutely nothing. Dietary fat can be stored as body fat, in the absence of dietary carbohydrates. Gary Taubes' claim "You can basically exercise as much gluttony as you want, as long as you're eating (only) fat and protein." is not supported by the evidence.

The low protein intake in Nutritional Ketosis, combined with the high serum cortisol that's almost inevitable on this way of eating, results in a loss of muscle mass. I give Nutritional Ketosis a thumbs-down.

Thursday, 10 July 2014

Only me! You don't want to be doing logical fallacies like that!

There can be only one video...


Here's only me on 9.7.14, at the Trafalgar Inn Aldershot, just before karaoke.
Only me! 9.7.14.

EDIT: And here's only me on 10.7.14, at the Lion Brewery Ash, just before the jam session.
Only me! 10.7.14.

From Here are the results after one month on my high fat, lower protein, SAME carbohydrate intake:-
"Fredrick Hahn said...
I've said this to Nigel before Tom Traynor and he insists he doesn't want muscles.

But to be fair to Nigel, he can indeed be 100% correct and at the same time be a blubbery, weak, mess of a man. You can be a great lung cancer doctor and smoke..."

"Tom Traynor said...
NK LOOKS terrible!--soft, fat and weak--and drum roll: "Doesn't want any muscle". So he is an absolute FOOL, too (loss of muscle mass predicting mortality--among MANY other facets). That's all the "science" I need."

What I actually wrote:-
"Nigel Kinbrum said...
Considering my age (59.25), I'm in pretty good condition. I'm 6' tall and weigh 198lbs. I have *no* desire to have big muscles or a 6-pack. Each to their own."

Misquoting me or quoting me out of context is a Straw man fallacy. Saying that my physical characteristics invalidates my knowledge is an Ad Hominem fallacy. In addition, saying that my lack of relevant qualifications invalidates my knowledge is an inverse Argument from authority fallacy.

Wednesday, 9 July 2014

Why you really can't outrun your fork.

Hat-tip to Yoni Freedhoff.
From http://www.blacksheepfitness.co.uk/you-cant-outrun-your-fork.html

See Effect of school-based physical activity interventions on body mass index in children: a meta-analysis.
"Meta-analysis showed that BMI did not improve with physical activity interventions (weighted mean difference -0.05 kg/m2, 95% confidence interval -0.19 to 0.10). We found no consistent changes in other measures of body composition."

Some people believe that if going to the gym isn't making them lose weight, they're not exercising hard enough. Chronically over-exercising can chronically raise serum cortisol, which makes the kidneys retain water, causing a stall in weight-loss, as well as causing raised fasting blood glucose, irritability, poor memory and a slower metabolic rate, due to the reduced conversion of thyroxine into tri-iodothyronine.

Don't over-exercise!

A healthy body weight is made in the kitchen, not the gym. Buy produce, cook it and eat it!

Although I totally support the use of low-carbohydrate/calorie diets for people with Insulin Resistance or Type 2 diabetes, now that I'm no longer insulin resistant, I can eat natural carbohydrates without any problems.

A medium-sized (orange-fleshed) Sweet Potato takes only 4 minutes to bake in its jacket in a 700W microwave oven. The flesh is moist & sweet, unlike that of a Yam or potato.

I eat the whole thing, including the jacket. It's very filling and I'm still able to lose weight. For active and Insulin Sensitive people, a Kitavan-style diet is absolutely fine.

Monday, 7 July 2014

Why Calories count (where weight change is concerned).

I have to add the words "where weight change is concerned", as calories have little to do with body composition or general health (unless somebody becomes morbidly obese).
From https://docs.google.com/file/d/0Bz4TDaehOqMKSXZHUUVxWnl5VTQ/edit?usp=sharing

Arguments used by Calorie Denialists include:-

1) Calories don't count because the human body isn't a Bomb Calorimeter and treats different macronutrients differently.

100g of liquid paraffin burns in a Bomb Calorimeter, yielding 900kcals. In a human, it passes through completely undigested. Ah-ha!, I hear you saying. This proves that the Energy Balance Equation is invalid. Uh, nope!

Calories in = Calories entering mouth - Calories exiting anus

As 100% of liquid paraffin calories entering the mouth exit the anus, Calories in = 0.

This is why Sam Feltham's "Smash the Fat" is utter nonsense. A significant % of the large amount of raw almonds he ate would have exited his anus incompletely chewed & undigested.

See the picture above? In the late 1800's, W.O. Atwater established Atwater Factors (3.75kcals/g for digestible Carbohydrates, 4kcals/g for Proteins, 5kcals/g for Ketone bodies, 7kcals/g for Alcohols & 9kcals/g for Fats*) using Human Calorimeters, not Bomb Calorimeters. Atwater Factors are pretty accurate.

*Fats containing different fatty acids have slightly different kcals/g. Fats containing long-chain fatty acids are 9kcals/g. Fats containing medium-chain fatty acids are ~8kcals/g.

For more information, see Calories ...

2) Calories don't count because Dietary Efficiency varies for different macronutrients.

Uh, nope! The amount of power generated by the body is regulated by a NFB loop involving the Hypothalamus, Pituitary, Thyroid Axis, also Uncoupling Proteins (UCP's), so as to maintain a body temperature of 37°C ±3°C. If this wasn't the case, different amounts & types of foods (also, changes in ambient temperature & clothing) would cause large variations in body temperature resulting in death, as the enzymes in our bodies function correctly over only a limited range of temperatures. ∴ Dietary Efficiency is irrelevant.

Power generated by the body (W) = Temperature difference between the body & ambient (°C) divided by Thermal resistance between the body & ambient (°C/W)

Sunday, 6 July 2014

Metabolic rate, diet efficiency and thermodynamics.

From Life and Death: Metabolic Rate, Membrane Composition, and Life Span of Animals

This post is based on https://www.facebook.com/richard.feinman.7/posts/667508920000715:- 
"When people say the laws of thermodynamics, they usually mean the first law, the law of conservation of energy. However, “conservation of energy” can be a sound bite, at the level of “Einstein said that everything is relative.” You have to know exactly what is being conserved. Precise definitions become very important. One of the many difficulties in understanding thermodynamics is that there are simple principles which seem obvious enough but their import is under-appreciated without a real example.

The first law says precisely that there is a parameter called the internal energy and the change (Δ) in the internal energy of a system is equal to the heat, q, added to the system minus the work, w, that the system does on the environment. (The internal energy is usually written as U so as not to confuse it with the electrical potential).

ΔU = q - w (1)

This is how thermodynamics is taught. To go to the next step you need to understand the idea of a state variable. A state variable is a variable where any change is path-independent. For example, the familiar temperature T and pressure P are state variables. It doesn’t matter whether you change the pressure quickly or slowly. The effect on the system is controlled by the difference between the pressure after the change minus the temperature before the change, that is, ΔP. The usual analogy is the as-the-crow-flies geographical distance, say, between New York and San Francisco. This is a state variable: it doesn't matter whether you fly direct or go through Memphis and Salt Lake City like the flights that I wind up on.

Now, U in equation (1) is a state variable. Any process that you carry out will have a change in U that depends only on the initial and final states. However, q and w are NOT state variables. How you design your machine will determine how much work you can get out of it and how much of the energy change will be wasted. Looking at the biological case, two metabolic changes with the same U have no theoretical reason why they should have the same relative amounts of heat and work, that is, the same efficiency (storing fat as compared to generating heat). Of course, they might but there is no theoretical barrier to difference.

In this, the first law contains the suggestion of the second law. The second law is what thermodynamics is really about.... It is the second law that embodies the special character of thermodynamics. Described by Ilya Prigogine, the Nobel-prize winning chemist and philosopher of thermodynamics, as the first revolutionary science, it is the second law that explains how one diet can be more or less efficient that the other."
Ref: Non-equilibrium thermodynamics and energy efficiency in weight loss diets.

To which I replied:-
"Uncoupling proteins (UCP's) vary ATP → ADP + heat, so as to maintain the human body at 37°C ±3°C over a wide range of ambient temperatures.

Therefore, "efficiency" is varying over a wide range, for all diets."

Followed by:-
"Here's an example:-

To maintain a body temperature of 37°C in an ambient temperature of 20°C, the body needs to generate ~1kcal/min (~69.8W).

If Diet "A" generates 30W due to metabolic processes, UCP's generate an extra 39.8W.

If Diet "B" generates 40W due to lower "efficiency", UCP's generate an extra 29.8W only.

According to Life and Death: Metabolic Rate, Membrane Composition, and Life Span of Animals:-
"Not all body tissues contribute equally to BMR. For example, ∼70% of the BMR of humans is contributed by internal organs that constitute only ∼7% of body mass..."

As humans can survive in a wide range of ambient temperature covered by a wide range of clothing, UCP activity must be capable of being varied from 0 (ambient temperature ≥37°C) to a high value (swimming in water at 10°C).

Therefore, diet efficiency is irrelevant, as UCP's equalise overall efficiency to equalise heat generation.

Saturday, 5 July 2014

Lies, damned lies and statistics, part n+1. Riera-Crichton et al.

In Macronutrients and obesity: Revisiting the calories in, calories out framework, the conclusion is:-
"Our structural VAR results suggest that, on the margin, a 1% increase in carbohydrates intake yields a 1.01 point increase in obesity prevalence over 5 years while an equal percent increase in fat intake decreases obesity prevalence by 0.24 points."

So, carbohydrates are fattening but fat is slimming, eh? I declare shenanigans! Two can play at that game.

In Effect of Dietary Protein Content on Weight Gain, Energy Expenditure, and Body Composition During Overeating, Bray et al increased kcals by 40% by adding Fat grams. Protein & Carb grams didn't change. ∴ Protein %E & Carb %E decreased by 29%.

Weight (fat mass) increased as Fat kcals increased ± some interpersonal variation.
From Fig. 6.

_Decreased P %E & C %E result in increased weight (fat mass).

∴ Increased P %E & C %E result in decreased weight (fat mass).

∴ Fat is fattening, but Protein & Carbohydrate are slimming! Q.E.D.

Do you see what's going on? Here's a summary:-

A diet contains A, B and C.
The amount of A increases, but the amounts of B and C remain constant.
A%E increases, but B%E and C%E decrease. %E means "as a percentage of total Energy".

In Riera-Crichton et al, A = Carbohydrate, B = Fat and C = Protein.
In Bray et al, A = Fat, B = Carbohydrate and C = Protein.

Friday, 4 July 2014

How low-carbohydrate diets are (incorrectly) explained to work.

Having explained how low-carbohydrate diets work, here are a few ways in which they don't work.
Uh, nope!

1) Hormonal clogs: This is a term used by Jonathan Bailor. I don't think he's referring to wooden shoes! The "clog", I'm guessing, is supposedly caused by that dastardly hormone insulin. Uh, nope!

See the following plots of RER vs exercise intensity after being on high-fat or low-fat diets.
RER = 0.7 ≡ 100%E from fat. RER ≥ 1.0 ≡ 100%E from carb.

The low-fat diet results in higher RER, so the body is burning a higher %E from carb and a lower %E from fat.

However, this doesn't make any difference to weight loss, as it's merely a substrate utilisation issue. In addition, when the body is burning a higher %E from carb, this depletes muscle glycogen stores faster, which lowers RER during the course of the exercise. So, it's not a problem.

2) Insulin fairies: During the night, the insulin fairy comes and makes your body store your bed-time carbohydrates as body fat. Uh, nope!

The only time that there's significant hepatic DNL is when there's chronic carbohydrate over-feeding. If you've been over-eating carbohydrates all day, bed-time carbohydrates will add to the chronic surplus and there will be significant hepatic DNL. Well, duh! Who knew?

If, on the other hand, you've been eating sensibly all day, there will be no significant hepatic DNL of bed-time carbohydrates. In fact, bed-time carbohydrates produce a calm feeling (due to increased serotonin) and a drowsy feeling (due to melatonin) making it easier to go to sleep. Enjoy your night-cap!

3) A Calorie isn't a Calorie, where weight change is concerned: "A calorie is a calorie" violates the second law of thermodynamics, therefore there's a Metabolic Advantage with low-carbohydrate diets. Uh, nope!

Where to start? Evelyn Kocur knows her Physics, so I'll start there. See The first law of thermodynamics (Part 1) and The first law of thermodynamics (Part 2).

From Second Law of Thermodynamics:-
"Living organisms are often mistakenly believed to defy the Second Law because they are able to increase their level of organization. To correct this misinterpretation, one must refer simply to the definition of systems and boundaries. A living organism is an open system, able to exchange both matter and energy with its environment."

People on ketogenic diets excrete very few kcals as ketone bodies. See STUDIES IN KETONE BODY EXCRETION. There is no significant Metabolic Advantage with low-carbohydrate diets.

How low-carbohydrate diets result in more weight loss than high-carbohydrate diets for people with Insulin Resistance or Type 2 Diabetes.

See The Battle of the Diets: Is Anyone Winning (At Losing?) for trials where insulin resistant people get more weight loss on low-carbohydrate diets than on high-carbohydrate diets, and insulin sensitive people get more weight loss on high-carbohydrate diets than on low-carbohydrate diets.

Although insulin is involved, it has nothing to do with "Hormonal clogs" or "Insulin fairies"!
The Aragon Insulin Fairy

The Energy Balance Equation


Change in Bodily Stores = Energy in - Energy out, where... 

Energy in = Energy entering mouth - Energy exiting anus, and... 

Energy out = BMR/RMR + TEF + TEA + SPA/NEAT

See The Energy Balance Equation to find out what the above terms mean.

People with insulin resistance & Type 2 Diabetes have no 1st phase insulin response to a sudden rise in blood glucose level. This introduces a time-lag into the negative feed-back (NFB) loop that regulates blood glucose level. If input level rise-time is less than the time-lag in a NFB loop, the output of the NFB loop overshoots. This is standard NFB loop behaviour. Trust me, I'm a retired Electronic Engineer. I've observed this (too) many times!

1) On a high-carbohydrate diet of high-GI carbs, blood glucose level rises rapidly, with a rise-time that's less than the time-lag in the blood glucose regulation NFB loop. Insulin secretion from the pancreas overshoots in a positive direction. The resulting postprandial hyperinsulinaemia results in rebound low blood glucose level. Rebound low blood glucose level results in postprandial hunger, as per Return of hunger following a relatively high carbohydrate breakfast is associated with earlier recorded glucose peak and nadir. Postprandial hunger results in over-eating. Energy in increases. Postprandial hyperinsulinaemia also results in postprandial sleepiness. Energy out decreases. ∴ Bodily stores increase.

2) On a low-carbohydrate diet, there are minimal fluctuations in blood glucose level. There are minimal feelings of postprandial hunger. Energy in decreases. There are minimal fluctuations in blood insulin levels. There is minimal postprandial sleepiness. Energy out increases. ∴ Bodily stores decrease.

In addition, there is a loss of water weight due to a loss of liver & muscle glycogen. This can be up to ~3lb (it varies from person to person). The kidneys can also increase their output for hormonal reasons. This can increase water weight loss to ~5lb.

Q.E.D.

P.S. In Metabolic Ward studies, food intake is tightly controlled, so postprandial hunger doesn't result in over-eating. Energy expenditure is also controlled, so postprandial sleepiness doesn't significantly affect energy expenditure. This is why varying Fat:Carb macronutrient ratios (with Protein held constant) makes no significant difference to weight. See Energy intake required to maintain body weight is not affected by wide variation in diet composition.

P.P.S. Inter-personal variations in postprandial hyperinsulinaemia, postprandial sleepiness & energy out explain the inter-personal variations in weight gain seen under hypercaloric conditions.

Thursday, 3 July 2014

Guest post: Philosophy of Science.

Being systematic, rigorous and quantitative, science is a good way to pursue knowledge. However, it is limited to a specific philosophical framework. The philosophy of science defines its limits, methods and presuppositions. Being the foundation of critical thinking, it’s a good way of investigating and testing our beliefs about the natural word, and more broadly what humans can know. Because humans are plagued with flaws in cognition, perception and memory, a system of methods was developed to compensate for those failings.


Epistemology

We turn now to Epistemology, the philosophy that deals with the nature of human knowledge, but also sets the limits of what’s knowable. There are many questions science cannot answer because they are scientifically unanswerable, as opposed to factual questions. Although many might not think in these terms, it’s hard to avoid doing philosophy in science.

Empiricism states that knowledge comes from sensory experience. John Locke is considered the first empiricist. He was concerned about the boundaries of human knowledge, and claimed that thought comes from experience, that experience is the essence of thought and stated:

“Nothing is in the mind that was not first in the senses.”

Locke recognized the limitations of sensory experience, and therefore the limitations of human knowledge.


The Epistemological Limits of Science

Science only deals with scientific claims, any claim can be scientific if it is practically testable and falsifiable. If the notion is testable it involves science. Science works within the philosophical framework of science. If all of the assumptions of science are correct, they should produce some objective, positive results overtime.


Pragmatism

William James and John Dewey developed a comprehensive philosophy based on a “scientific” response to experience. For them, universal knowledge of what lies beyond experience is impossible. Dewey understood Pragmatism as prospective empiricism, and that science should be a pragmatic belief system. Pragmatism was a philosophy built on an experience-based conception of scientific knowledge.


Logical positivism

Later came the logical positivists. For them, science should be adequately reconstructed in empiricist terms, as a linguistic kind of thing with a set of sentences with certain properties. This is the best way to relate evidence and meaning, they thought, and what makes science special. This logical positivism approach to science became known as rational reconstruction.

An empirical interpretation of such language was need such as “There is an object X, and object has property P.” However science isn’t just about observations and properties, but also explanations. Observations and properties can be listed but we also need to elaborate a theory and make predictions, and this goes beyond experience. If science must limit itself to experience, how can it also go beyond experience?

How can we say object X is fragile, without violating empiricism and enter the realm of metaphysics? Fragile is not an observation term, but a disposition term. To solve this problem we have to place object X under certain test conditions. “X” must be defined as “fragile” in the condition that if we were to strike it, “X” would break”. This is a counter-factual conditional and cannot be defined in terms of the logical or observational vocabulary. Such conditionals depend on how the world would behave if it were different that it presently is, that is, under experimental conditions.

We need to move away from the observational level in order to explain phenomena and generate predictions about the world and increasingly complex phenomena. Thus, vocabulary must keep expanding, interpreting new terms and creating statements linking those terms.

The structure of a scientific theory is like a mathematical theory, and general laws serve as axioms, such as Newton’s laws. New statements provide empirical meaning that directly connect to observations. Sentences or statements that does not hook up to other statements are called isolated sentences, they don’t generate new predictions, and don’t add anything to the theory. Another way logical positivists avoid metaphysics is by refusing theories or statements about unobservable reality. A statement is only meaningful if it can be verified observationally.

For the logical positivists, the connections between theoretical terms are crucial for deriving observations, not for describing reality. Many statements in a scientific theory are inferences, saying that it is all right to infer this from that, that’s the instrumental conception of scientific theories. Science doesn’t make statements that go beyond observation, but make statements about patterns in experience.

A scientific theory is an axiomatic system, all relevant observation statements are deduced from a set of logically consistent, true theory statements, and upon rules for correlating theory and observation.

Logical Positivism persisted from the 1930s into the 1960s, offering hope that a classically objective theory of scientific knowledge was possible, but in the end, Logical Positivism failed. Carl Hempel criticized the separability of theory and observation statements, while W. V. O. Quine dismissed the distinctions between analytic and synthetic sentences, and between theory and observation statements. The verifiability criterion didn’t resist because some non-verifiable terms were inevitable in meaningful theories.


Methodological naturalism and assumptions

The methods of science are called methodological naturalism, in simple terms it underlines that material effects must have material causes. The material includes all macroscopic matter, all forms of energy, dark matter and dark energy recently discovered. This philosophy follows natural laws, therefore it cannot invoke miracles or supernatural phenomena as an explanation for any experiment or observation outcome. Science requires that we follow the methods that assume there is nothing beyond the natural world, and does not rely upon any supernaturalism.

For example, one scientific assumption is that of an objective reality. Without that assumption it’s impossible to investigate how the universe works. Another assumption is that the world is predictable and, therefore, knowable.


Falsifiability

Non-material causes cannot be falsified; therefore, they fail to meet a necessary criterion for science - they are not constrained in any way, they have no limits, they do not follow the laws of nature of material cause and effect. In short, constraint is necessary for falsifiability.

Bertrand Russell explored the relationship between testable and untestable claims and created an analogy known as Russell's teapot: a hypothetical teapot proposed that is orbiting the Sun between Earth and Mars to make the point that not all claims that cannot be proven false should be accepted as true.

Therefore, one cannot prove the teapot doesn’t exist, but is it reasonable to conclude that it does exist?

This example is used to make the point that the burden of proof for any scientific claim lies with those making the claim. The inability to prove something false is not sufficient justification for the claim.

This also raises the issue of proving a negative in science. While it’s not possible to absolutely prove the non-existence of something, given what we know about the laws of science and nature we might be able to demonstrate that something is impossible.


Pathways and methods of science

An observation leads to a hypothesis, and the hypothesis is then tested by an experiment. After the results, the hypothesis is refined. Then, the experimental phase is repeated.

Observation → hypothesis → experiment → refine → repeat

However, science can follow many pathways, for example, a hypothesis may come before a single observation.

Scientific methods develop a model of how the world works. Hypotheses and theories must explain nature and generate predictions about observations. Scientific theories are explanations for a pattern of observations, when there is more than one explanation that can account for data we already have, an experiment can be a way to separate them. A theory is only useful if it makes predictions that are different than other existing theories.

The highest form of criticism is: “not even wrong”. This is a common phrase used in scientific criticism, meaning that the theory does not make specific predictions and is therefore useless, an idea that can’t be tested or refuted isn’t even wrong.

All conclusions in science are provisional and subject to further evidence and theories. There’s no metaphysical certitude, scientists and critical thinkers need to be comfortable with uncertainty.


Occams razor

Another way to separate two competing theories that account for the same data, if there is no empirical method, is a philosophical rule of thumb called Occams razor, or the rule of parsimony. Occam’s razor states that the theory with the fewest new (ad hoc) assumptions is preferred to make the theory work, in principle that theory at least should be preferred until eliminated. Otherwise, we could endlessly generate ad-hoc theories to explain any given phenomenon.


Paradigm shifts

Science is a process of refinement. You can have paradigm shifts, resembling Kuhn’s paradigm shift model, but as science progresses, the process of refinement becomes more apparent.

For example, Einstein’s relativity did not prove Newton’s classical ideas wrong, it was a refinement to Newton and not a total replacement.

In many sciences, while refinements are possible, fundamental knowledge will not be overturned, because they are established to a high degree and have solid scientific knowledge.

For example, electrons do not spontaneously decide to change their fundamental properties.

Hard science should be considered so by its rigorous methods, objective outcomes and systematic observations, and not by the subject matter.


Empiricism

Berkeley, George. Three Dialogues between Hylas and Philonous. New York: Oxford University Press, 1998

Hume, David. A Treatise of Human Nature. New York: Oxford University Press, 2000.


Pragmatism

Dewey, John. Experience and Nature. New York: Dover Publications, 1958.


Logical positivism

Ayer, Alfred Jules. Language, Truth and Logic, 2nded. New York: Dover Publications, 1952.

Balashov, Yuri, and Alex Rosenberg, eds. Philosophy of Science: Contemporary Readings. pp. 132–140. New York: Routledge, 2002.

Boyd, Richard, Philip Gasper, and J. D. Trout, eds. The Philosophy of Science. Cambridge, pp. 71–84. pp. 299−315. MA: MIT Press, 1991 Science.


Science

Asimov, Isaac. Asimov’s New Guide to Science. London: Penguin Books, 1993. Asimov explains the process of science using classic historical examples, offering the human dimension of how science works.

Klemke, E. D., Robert Hollinger, and David Wyss Rudge ,eds. Introductory Readings in the Philosophy of Science. Amherst: Prometheus, 1988. The standard introductory text to the philosophy of science; better suited for a classroom than casual reading.

Hines, Terence. Pseudoscience and the Paranormal. Amherst: Prometheus Books, 2002. Hines takes a no-nonsense scientific look at paranormal belief in popular culture.


Blogs

Novella, Steven. “New Scientist on Miracles.”NeuroLogica Blog. http://theness.com/neurologicablog/index.php/new-scientist-on-miracles

Novella, Steven. “Science and Faith.” NeuroLogica Blog. http://theness.com/neurologicablog/index.php/science-and-faith

Novella, Steven. “The Context of Anecdotes and Anomalies.” NeuroLogica Blog. http://theness.com/neurologicablog/index.php/the-context-of-anecdotes-and-anomalies


For more information on Sérgio Fontinhas, see Big Fitness Project.