First glance, the next topic of our discussion is very simple. We will talk about health. It seems that everyone knows what is health. And many people will tell, well, the health is just a collection of norms and status when all parameters of body are within normal ranges. But it looks like harmful oversimplification of the reality. Health is not just the status when all parameters are within normal limits. It is a little bit more complicated. Let us compare norm and health. Health is something absolute. It is absolute category, but norm is always relative. And I will show you that norm is relative. First thing, norm is relative historically. What was believed to be normal 100 years ago no longer belongs to norm now. If you will open the old good classical text book of Internal Medicine published in the beginning of 20th century, if you will look there, what did they write about the normal white blood cell count in blood? It is written there that healthy male has between eight and 12,000 of white blood cell per cubic milliliter of blood. Excuse me, for modern medicine 100 years later, 12,000 per cubic milliliter is already leukocytosis and 8000 which was lower limit of normal count 100 years ago. Now, it is upper limit. It means, that we are still healthy like our great grandfather were healthy 100 years ago. But they were healthy with BBC count 8-12, and we are healthy with BBC count 4-8000 per cubic milliliter. What's the difference? The difference is dual. First thing, 100 years ago, almost nobody did not get vaccination. And since that period, many generations of people were subdued to mass problems of vaccinations against infectious diseases. And second thing, 100 years ago, infection diseases were common in every third man on autopsy in Germany. They could review the signs of tuberculosis, in Germany, one of the most progressive countries of the world with the highest hygienical standards of population, in every third person, tuberculosis which is not the case for modern people. That is why, historically, the norm of white blood cell count is different. It was 100 years ago and now, we have absolutely different norm. Second thing, norm is relative geographically, which is normal here for this environment, for this condition, no longer is considered to be normal in other place of the earth. For example, if you live in high altitude, for example in Bolivia, high hemoglobin and high red blood cell count is normal for you. It is adaptation for hypoxia. You are healthy, but you have high normatives. Now, you come to this city, many thousands kilometers to the north and you leave almost at zero altitude at the level of sea and medical doctors here may mistakenly think that you came here because from the local point of view, from the point of your local ecology, local geography, such a higher level of red blood cell is abnormal. And they will look for reason but the reason is simple. You are from Bolivia. That's why norm is relative. It is relative historically. It is relative geographically. And the most important thing for different situations, we have different norms. For example, if I sleep in my bed, I have a relatively lower arterial blood pressure. But I wake up. I had a cup of coffee, maybe even three cups of coffee. After that, I went to my office, and I'm driving, and they have traffic jam, and I'm nervous, and I'm condemning everyone around me and I'm quarreling to next driver. And because of that, I have stress. I am still healthy as I was healthy in my bed. But I am healthy with absolutely different numbers of arterial blood pressure. It get higher. Does it mean that I became sick? No. No. Healthy person is a person which has appropriate level of parameters, not fixed level, but level appropriate for certain situation. If I am able to increase blood pressure in stress and to decrease it back immediately after finish of that stress, that means I'm healthy. So health is not certain normative. It is individual dynamical situational optimum. That's the difference with norm. Normative is just statistically typical for majority, fixed standard, and health is an individual dynamical situational optimum. Look at this picture. English pathologist, Williams, in 1960 said, "An individual normal in all aspects is a phenomenon most unusual among all existing." If everyone has least, let me say, 200 parameters blood glucose, blood cholesterol, height, body mass and so on and so forth, 200 parameters. And by statistical law and according to bell-like Poisson distribution, 0.5 percent of population are beyond normal interval. For every one of that 200 parameters, 0.5 percent for every parameter, 200 parameters. If you will calculate, if you go check all the parameters in every person, well, you will find that no one has not all of them in normal range. At least one is abnormal. Where are the healthy people? It doesn't mean that there is no healthy men in the world. It means that this criterion is wrong. You cannot mechanically distinguish health and disease on the basis of some statistical normatives. It is a wrong approach, harmful oversimplification. Well, if the health is not a status when all parameters are in stable fixed norm, then what is health? Different clever people gave different reliable and interesting definitions. Let me share these definitions with you. Ioakim Romanovich Petrov, famous Soviet military patophysiologist, "Health is life of a capable individual adapted to changing environment." In other, also military patophysiologist and medical philosopher Vitaliy Petlenko, absolutely different definition, romantic, humanistic, inspiring. He said, "Health is state of body and spirit which makes us nice, free and loving." Please compare these two definitions. Both authors were generals of Soviet army, of medical forces but absolutely a different approach. Strict or relaxed, romantic or academic. The next definition by Osip Glozman, Soviet pathologist of the middle 20th century, he said, "Health is a resistant living process derived from interaction of body and environment philogenetically caused life endurance." So you can see that this person involved evolutionism in the definition of health. Another person, and I have already shown you this person when we discussed the definition of disease, Karl Marx. He gave very interesting definition of Health. "Health is an aggregate of physical and spiritual capabilities in disposal of an organism, alive human personality." Too philosophically, I think. We need to be closer to National Sciences. For example, let me give you definition of health by Alexander Korol'kov, Soviet Philosopher. He said, "Health is a measure of biological competitiveness of a living system." So, if you are able to take part in competition and to be successful, it means you're healthy. If you are not able, not competitive, it means your health has limitations. Good definition but also a little bit unilateral. That's why I give you another one by Domestic Pathophysiologist, Pavel Horizontov, "Health is state of vigor, well-being and good working capability." Sometimes medical doctors and representatives of other non-medical professionals, they try to embed sociological element in the definition of health. The nature of human being is dual. It is bio-social. That's why in my opinion, the definition of health shall avoid abundant sociologism, should not be too sociological; otherwise, we may come to very paradoxic definitions like World Health Organization definition that "health is state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity." Let me say that it is not very wise definition. It is rather formal. Health is absent of disease. That's not enough to comprehend the phenomenon of health. And according to this definition, every person which is imprisoned for example, well, automatically is not healthy because health is state of complete social well-being. Listen, millions of people are not in social well-being. It does not mean that they are not medically healthy. That's why you should know the social approach to definition of health. But you should accept it critically. For example, criminal and procedural law in Russia and in many other countries gives very simple definition of health: "Health is status when a person has not sick leave." But that is not enough for a professional medical doctor because medical doctor is a person who must decide if we shall issue sick leave for this individual or we shall not. And if you will rely upon this stupid socioligizated definitions, you will be not able to be the key figure in all that matters. That's why I like a less sociological and more, let me say, general, more cybernetic definitions of health. For example, definition by Luis Ruyter Radcliffe Grote, "Health is free responsibility of organs and body." Free responsibility, good definition. If you are free to dispose your potential, it means, you are healthy. Relation between health and freedom is very important. Health is biological freedom in fact and I appreciate a definition of health given by Arthur Jores, "Healthy means able to dispose self possibilities." If you will remember the definition of disease as life limited in freedom, you will agree with that Grote and Jores definitions of health. And in conclusion, let me give you my own definition of health. "Health is relatively more stable and less imperfect form of individual life, which provides economical optimal least dangerous mechanisms of adaptation for environment and allows to secure some functional reserve for its change." If you are healthy, you are going to change environment around you for your own benefit but for that living system needs some resource. So, if you have this resource to change environment for your benefit, that is a sign of health. Shortly say, health is life minimally limited in freedom, in freedom of strategic choice. If you are healthy, you are free in choice. If you are in disease, your freedom of choice is more or less limited. So, we can speak about some criteria of health, enough of functional reserves. Freedom of choice for the forms, scales, and ways of reaction, it exists in health and it no longer exist in disease. Minimal rates of entropy growth. Entropy always grows in living system. They are also subordinated to the laws of chemistry and physics and their entropy also grows. But in healthy state, it grows with minimal possible rates. And in health, you have maximal possible coefficient of efficiency. For example, for healthy heart, coefficient of efficiency is over 40 percent, over 40 percent. And in any cardiac disease, it decreases. So, probably, if we will look for criteria of health, we should mention the ability of actually changing the environment for the benefit of living system. It can be displayed in labor, but it can also be displayed in play, in sex, in search. We should not concentrate on one particular form of environment change in captivity. Play in kids, labor in adults, sexual activity, research activity - they all can be the signs of health. Well, there are some other criteria of health and you can go through that during self-studies and probably at this point, our lecture is finished. Thank you.