Wolfhnd

"The individual I'm referring to has never been able to exist independently," Neither would any human because we all helpless at birth and as a social animal fairly helpless as individuals. We are just communicating here to try and help each other as social animals. The hope is that we can learn to full cooperate at some level by establishing a harmonious atmosphere.

You will find it hard to offend me mothythewso There are some language problems here. A brain dead human is a subset of humans, a retarded human is another subset. A human fetus is a developmental stage of humans. "Human" is a scientific classification that distinguishes humans from non human animals. Scientifically a human is a human and there are subcategories each of which is well defined. Your human regardless of any subcategory you may fit. The concept of species is convenient but not necessarily precise. Life on the other hand has no accepted definition, scientist cannot agree. With no accepted definition of life the OP is not a valid scientific question outside of defining what is not alive which is pretty easy to do. We then turn to a scientific attempt to determine what constitutes an individual organism. A fetus is part of organism and only becomes an individual organism when it is capable of carrying out it's biological functions independently. So a human life begins when a fetus can survive independently. I just don't see this as a hard question. The assertion that the definitions carry a cultural bias is a bit silly. If you want to say that some organisms that are scientifically classified as human are not really human then you have moved outside the realm of science.

You cannot have your cake and eat it. We do not have the economic resources to switch to "clean" energy in the short run, the crime is in not using foresight at all. The most annoying aspect of Darwinian economic policies is that the people proposing them don't understand Darwin, that life is more about cooperation than competition, and that evolution equals extinction. Systems that have no foresight, are overly competitive, and fail to understand nature are doomed. The problem with liberal policies is that they demand perfection now. No one likes cost benefit analysis because it interferes with their agenda.

If you think of emotions as feelings then it is easy to see them as the physical and psychological manifestation of instincts. Love, anger, fear etc. are primary emotions which in turn are moderated by consciousness to produce secondary emotions. See Shaver for a detailed list > http://changingminds.org/explanations/emotions/basic%20emotions.htm The more primal an emotion is the less likely your are to be conscious of it. I would suggest that this hierarchical system evolved in response to the concentric rings of increasing complexity within the brain structure itself. In other words old structures are not discarded as new structures are added. More importantly there is an advantage in keeping a degree of isolation in function. Compare it to a computer, there is the mother board bios that regulates basic function and maintains the hardware, next you have the operation system that allows other programs to run, final you have the programs that we consciously interact with. The user is unaware most of the time that any of the underlying systems even exist. What is easy to miss in this analogy is that the efficiency of the conscious interface is dependant on the "intelligence" of the underlying systems. Maintaining a healthy, active emotional, base is equally important to our ability to think clearly and efficiently. If any part fails the system will not function properly. Since emotions are actively engaged in imagination they increase our "creativity" "A human being is a part of the whole, called by us ‘Universe,’ a part limited in time and space. He experiences himself, his thoughts and feelings as something separated from the rest - a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty. Nobody is able to achieve this completely, but the striving for such achievement is in itself a part of the liberation and a foundation for inner security." Albert Einstein

How precise do you want to be, at what point is your "truth" statistically significant to others.

No one here is likely to argue with that position. The problem is that you would have to include the entire evolutionary, biological, neurological, ecological and psychological body of knowledge on homo sapiens to refine your definition. Who wants to do that? Even then a human body is still a human because in the end it's a question of DNA not brain waves. Science can be very helpful in determining when someone is brain dead but is not much use in determining when to pull the plug. Off topic warning: In the case of the retarded individual you cannot divorce your views from the views of others unless you have established a higher moral imperative. If other people view the individual as human you may want to as well.

The question here has become whether or not science can define what human life is? It's a three part question. Can science define what life is? Can science define what a human is? Is human life sufficiently abstract an idea that empirical data alone cannot define it? Despite considerable debate on whether viruses are alive or not science has done a fairly good job at uncovering the principles by which life has evolved and is sustained. So to the first question I think that with certain minor reservations the answer would be yes. Science can define life. The second question is more difficult. There are scientific definitions for what the word "human" means. For example you can start with applying more precise terminology such as "anatomically modern Homo sapiens". You can trace roughly the evolutionary history and pick an arbitrary point at which hominids became human. It's possible with considerable accuracy to define the physiological characteristics of being human. At some point you will however be forced to turn to what is known as the "soft" sciences psychology, anthropology, ethology, etc. It's not enough that you describe the physiological structures that separate human from non human animals and will need to address function as well as physiology. Since our phenotype involves observable behavior assessing abstract properties such as intelligence becomes necessary. Considerable advancements have been made in understanding human behavior and despite the nature verses nurture debate it can be said we understand human behavior. The next step in defining what makes us human is to understand the environment that is inseparable from being human or human culture, tool use etc. Each one of these steps become less precise as the subject matter becomes more abstract. Science has done a remarkable job at using empirical data to quantify each of these aspects of being human more or less precisely. So the answer to the second question is yes. Science can define what a human is. It's with the third question that science begins to fail us. Abstract ideas by definition do not have real world counterparts. Take math for example. Math is an abstract language that while having considerable utility at unraveling the mysteries of reality it is fundamentally built on absolutes. Science is a probabilistic enterprise resistant to absolutes. The tools of science may be abstract and absolute but the answers are always an approximation of reality. The third question I have no answer for because it isn't clear if the question itself is valid. It's only a valid question in relationship to other questions that are inseparable from the motives of the person asking the question.

Science is relevant to this topic for a few reasons. Science defines viability as medical expertise allows earlier and earlier postpartum survival. It's not viability per se that defines viability as a moral distinction but it is in reference to the mother and fetus being inseperable. If you make fertilization the point at which human life begins then any unprotected sexual intercourse become a potential abortion. Morality would then dictate that only artificial fertilization was moral when it is available. Science may not be defined by philosophy but philosophy must be restrained by science. What you know and your intent is part of ethics. If the courts call on science to rationalize a decision it is not ok for scientist to say I don't know when in fact they have relevant information. Let the courts decide what the questions are and answer them honestly. Science has made birth control widely and cheaply available. Birth control should always be considered preferable to abortion. Complication arise when birth control is abortive and scientific effort should be focus on avoiding abortive birth control. Scientist are morally obligated to speak out when religious leaders imply false or misleading conclusion about scientific issues related to abortion. Science advances faster than social mores and science is by nature is empirical. Moral philosophy on the other hand is about absolutes not accessible by the scientific method. Scientist are not free to act outside the bounds of moral standards and therefor have to partake in political matters as citizens not experts. The social sciences will be called on to answer some of the questions about social values, psychological impacts and other related issues. They should take as much care not to insert bias into the political issues as they take with their studies. Moral issues concerning non human animals arise if perception and thought alone is the standard for valuing life. Scientist should take a stand against religious leaders who argue that humans are unique by kind when the overwhelming evidence suggest it is by degree. Scientist must not dismiss moral issues as being irrelevant to their work. Everyone has moral obligation in everything they do. This is especially important to how scientist present themselves and the impact it may have on public perception. I could go on but all these things are philosophical questions not science.

Interesting discussion but it certainly no longer belongs in this sub forum?

Sexual Dimorphism is certainly an interesting subject especially in non human animals. In humans it is relatively modest. "Body mass dimorphism varies dramatically among primate species, both present and past. For most anthropoids, males are bigger than females (4–8). Humans today display relatively limited sexual dimorphism (≈15%), whereas some of the other hominoids (gorillas and orangutans) are highly dimorphic (>50%) (5, 9). Body mass is easily determined in living species. For past nonhuman primates and human ancestors, mostly represented by fragmentary fossil remains, body mass is far less accessible." http://www.pnas.org/content/100/16/9103.full Another explanation for gender differences is based on the hunter gather lifestyle presumed for humanoids. Again the traditional view that men were providers and woman babysitters is questionable. Modern hunter gather societies show a more balance nutritional contribution. It seems to range between hunted and gathered ratios of 60 40 and 50 50. Here is an article on hunter gather nutritional distribution from meat etc. http://ajcn.nutrition.org/content/71/3/682.full At the moment I'm inclined to believe that human sexual dimorphism can at least partially be accounted for by nutritional demands. Reproductive success is enhanced if females have bodies with lower nutritional demands allowing for a higher percentage of nutrients to be available to a fetus. Of course this would not be the only factor and many are vaguely covered by other posts in this thread. The following is off topic but addresses the issues raised concerning the appropriateness of the original post: I wanted to focus for a minute on physical differences because behavioral differences are less accessible and more likely to be environmental than innate. That said we are not blank slates and some of the impetuosity of the original poster may be a reaction to the political nature of gender norming. The goal of research should not be to demonstrate or justify sexual equality but to enhance our understanding of how to improve the health and well being of both sexes. It does seem clear that the original poster wanted to use research to promote views that would lead to sexual discrimination which is reprehensible. The way to counter that is too insist on equal opportunity not true equality. Considering the plasticity of the human mind biological differences between individuals is less important than desire and a positive attitude enhanced by the appropriate environment. That doesn't mean we should push individuals into positions they are likely to fail at based on misplaced ideas about equality. That behavioral differences rooted in genetic differences between the sexes should be expected is self evident. Biological difference are important to explore but biology alone will not answer all the questions. No matter how much we may dislike it, anecdotal evidence will have to be considered by archaeologist, sociologist and other soft sciences. In the end satisfying philosophical answers to some of the questions can not be based on empirical data. The philosophical answers however must be restrained by relevant scientific observations.