Stem Cell Regulation - 633 Words

Skin with its hair follicle is an excellent system to study molecular mechanism of stem cell regulation. Due to constant need of tissue regeneration, it has abundant number of stem cells. Hair follicle consist of a permanent portion- sebaceous gland and below it is a bulge area, which houses- Hair follicle epidermal stem cells(HFSCs). Bulge also provides niche for melanocyte stem cells interspersed between HFSCs. Behavior of the two stem cells is well coordinated. Differentiating melanocytes transfer pigment to terminally differentiated hair follicles (Nishimura et al., 2002; Tanimura et al., 2011; Rabbani et al., 2011).Hair follicle undergoes cyclical bouts of 3 phases-anagen (phase of active growth), catagen (destruction phase) and telogen (rest phase) (Hardy, 1992). HFSCs give rise to daughter stem cells which are retained in the bulge area and others form, either epidermal progenitors which migrate upwards during tissue repair or it forms hair-matrix progenitors which migrate bel ow to form hair shaft (Niemann Watt 2002; Oshima et al., 2001; Taylor et al. 2000). In early 1990s, HFSCs were located in the bulge region by label retention studies (Cotsarelis et al., 1990; Morris and Potten, 1994). Later in 2001, presence of HFSCs in bulge area was confirmed by transplantation experiments. When lac-z labeled bulge region from adult mice was transplanted into hairless mice, lac-z labeled cells formed morphologically distinct hair follicle (Oshima et., 2001). Lineage tracingShow MoreRelatedSCI Case Study1591 Words   |  7 Pagesusing stem cell therapy, so I’ll try and provide you with as much information as I know. Currently in Australia and around the world, there are no proven cures for SCI using stem cells, this is according to the Australia and New Zealand Spinal Cord Injury Network (Stem Cell Interventions for Spinal Cord Injury, 2009) and icord.org (Steeves et al., 2012), both leading organisations in SCI treatment. There are however, clinical trials and research going on around the world that use stem cells to treatRead MoreStem Cel ls Essay1699 Words   |  7 Pagescontroversial research in stem cells. This technology offers hope to millions who are victims of a multitude of diseases and disorders. It can be used to regrow limbs, create organs, attack genetic diseases, treat malfunctioning bladders, etc. However, this same technology is also one of the most controversial debates in science today. If you type â€Å"stem cells research† into your Google search bar, you will most likely find not only advances in this field or a basic overview of stem cells, but articles onRead MoreStem Cell Essay939 Words   |  4 PagesInduced Pluripotent Stem Cells and their use in Cardiac Regeneration Introduction Myocardial infarction (MI) is the leading causes of mortality and morbidity in the world. Ischemic heart disease, where the oxygen supply to the myocardium is restricted, is a common cause of an MI. Myocardial injury results in loss of cardiomyocytes (cardiac muscle cells) due to apoptosis, and the development of necrotic myocardium, eventually leading to heart failure. The formation of the necrotic myocardium causesRead MoreStem Cells And The Future Essay1441 Words   |  6 PagesENC 1101-20M 1 December 2016 Stem Cells and the Future What exactly are stem cells? How can the use of these cells benefit us and how exactly are they acquired? Believe it or not stem cells have been in play when it comes to medicine since the 1950’s in France (Steenblock 1). This topic is very controversial and I surmise that it is strongly due to the lack of knowledge when it comes to stem cells and their importance. I, myself, am very intrigued by stem cells and my goal is to define whatRead MoreA Research Study On Stem Cell1225 Words   |  5 Pages My research about stem cells, I will be talking about what a stem cell is. Why are stem cells important from a medical perspective? How are stem cells being used today? Where do scientists get stem cells? Why is so much controversy over the stem cells? How does a zygote develop into a baby? Why a zygote is considered a stem cell? A stem cell is an immature cell that can help reproduce different types of cells throughout the body. There are three types of stem cells that I will be focusing on : adultRead More Stem Cell Research Essay1316 Words   |  6 PagesStem Cell Research What is a Stem Cell? Stems cells are immature cells found in embryos that can develop into any kind of specialized cells. They can form virtually any cell of the human body. These types of stem cells are known as pluripotent cells. Multipotent cells are stem cells that are more mature; they can be found in adults and children. Multipotent cells are not as flexible as pluripotent cells, as they have already developed into more specialized human cells. Benefits of StemRead MoreResearch On Stem Cell Research1582 Words   |  7 Pagesand dilemmas is stem cell research. The conflicts are specific types of stem cells are unethical and not morally right to research on, but not all stem cells are this way. Stem cell research is the study of different types of stem cells and their possible clinical uses. Stem cells can be developed to act as treatments for different types of illnesses and diseases, but currently no push for funding the advancement of research on stem cells are being taken. Even though some stem cells create conflictsRead MoreStem Cell Research And The Medical Field Essay1736 Words   |  7 PagesStem cells have become one of the largest research fields in the Department of Regenerative Medicine. They are often referred to as the â€Å"building blocks of nature† due to their ability to transform into any type of cell in the human body. It has led to the controversy of the possible chance that stem cells can regene rate organs, and cure life threatening diseases. This topic has been publicly discussed among scientists and healthcare professionals. There are different types of stem cells, such asRead MoreThe Controversy Over Stem Cell Research1169 Words   |  5 Pagesyears, stem cell research has become a prominent way of treating: heart disease, cancer, HIV/AIDS, spinal problems, and much more ; moreover, in recent years as Stem cell research became more popular, it has sparked controversy over the religion aspect of stem cell research. Stem cell research begins with culturing an embryonic cell and then injecting the stem cell into the area of concern(Robertson). Pluripotent stem cells are gathered and used to treat the areas, pluripotent stem cells are thoseRead MoreThe Controversy Of Embryonic Stem Cells1034 Words   |  5 PagesFor decades, researchers’ use of stem cells has caused a controversy and the consideration of the ethics of research involving the development, usage, and destruction of human embryos. Most commonly, this controversy focuses on embryonic stem cells. Not all stem cell research involves the creation, usage and destruction of human embryos. For example, adult stem cells, amniotic stem cells and induced pluripotent stem cells do not involve creating, using or destroying human embryos and thus are

The Unethical Practices Of Casinos - 2880 Words

The Unethical Practices of Casinos When walking into â€Å"The Strip† in Las Vegas, an instant feel of excitement rushes up. The flashy neon lights paired with glimpses of amazing acrobatics on gigantic screens easily brings up the energy of tourists, businessmen, and gambling addicts. You may wonder how a once stranded desert can transform into such a paradise of skyscrapers. The answer lies in casinos. In the early 1930s, gambling was legalized throughout the state of Nevada and casinos began to flourish (Dunstan, 1997). The economic growth in Nevada, especially the city of Las Vegas, has improved tremendously by the creation of casinos. Many people were employed since the operation of casinos requires a huge amount of labor, skill, and expertise. In addition, local retail sales also increased from casinos when gamblers visit the stores to spend their winnings on various items and products (Garrett, 2003). As a result, many state governments began to legalize casinos in order to boost their economies and increase employment. As of today, there are roughly 1500 casinos in the United States and they generate almost 65 billion dollars in revenue (â€Å"Facts on U.S Casinos† 2013). However, casinos use immoral methods to achieve this incredible feat of big profit with few government interventions. While the city of Las Vegas becomes more prosperous than before, many citizens los e their fortunes or even lives by the immoral business practices implemented by the casinos. Even though theShow MoreRelatedControl at Sands1673 Words   |  7 PagesThis report seeks to examine and evaluate the gaming control practices implemented in Sands Hotel and Casino before exploring the possibilities of its application in other gaming casinos and industries. The control system at Sands comprises of its control of cash and the movement of cash within the casino and, control of operation at the casino table. The control of cash at Sands is further subdivided into accountability, standard operating procedures during filling and security at the countroomRead MoreBlog 37 - Microgaming Evolves With New Evolution Gaming Partnership1781 Words   |  8 Pagesonline casino industry as a whole has been fairly notable over the years, but on case-by-case basis it is a little more difficult to define. However, one company in the field has recently made a very public move that can definitely be summarised as a true signal of intent. Microgaming has recently announced that they will join forces with Evolution Gaming to create a new live casino platform. It is safe to say that when two industry heavyweights like this come together, the online casino portalsRead MoreCooking the Books Essay1043 Words   |  5 Pagesexplored to see if there was a violation due to the unethical behavior of the company’s management and the inaccuracy of the company’s financial information. Keywords: Integrity, Ethics, Sarbanes-Oxley, Fraud Cooking the Books The problem is that the accounting manager has ordered his employee to falsify the books so that the company can show higher revenue in their current year in order to meet volume for a management bonus. These actions are unethical, fraudulent and may violate the Sarbanes-OxleyRead MoreThe American Gaming Association ( Aga )1465 Words   |  6 Pagesthings of value to the athletes in order to influence, or attempt to influence, the final score of both football and basketball games† (Fish). Manni and Karam paid players to â€Å"point-shave† to guarantee they would win their bets. Point shaving is â€Å"the practice by favored teams of attempting to win by less than the point spread to yield profits for gamblers who bet on the underdog† (Bernhardt and Heston). In 2007, NBA referee Tim Donaghy â€Å"started making NBA bets†¦and didn’t hesitate to wager on games heRead More3.0 Islamic Banking Now that, Islamic law has been defined and explained in detail, Islamic Banking600 Words   |  3 Pagesrules that govern investment behaviour in Islamic banking (Suleiman 2001): 1. Interest (Riba) 2. Deception/Uncertainty (Garar) and Change/Speculation (Maiser) 3. Trade (Haram) 4. Support Islamic tax system (Zakat) Alongside these four rules, unethical behaviour needs also needs to be considered. Followed, on I will discuss each of these four/five compliances of Islamic banking. 3.1 Interest (Riba) Interest, also known as Riba in the Quran is strictly prohibited in Islamic banking. It is the keyRead MoreThe Philosophy Of Virtue, By Jeremy Bentham And John Stuart Mill Erect The System Of Utilitarianism Essay1544 Words   |  7 Pagesnow my understanding that there is a difference in experimentation between â€Å"research† and â€Å"practice.† For example, experimentation by means of practice would be that a physician might recommend a new medication (if other have had fail to work) to find out if this new drug would be more efficient. However, if the physician is trying to experiment with the sole purpose to do research, this would be unethical, as it is forbidden; before a medication is out for a physician to use, lengthy studies/researchRead MoreThe Work Of Dr. Seuss1336 Words   |  6 Pagescommunities like Springfield and Holyoke. Considering the work of Kathryn McDermott, this research will highlight how this myth Dr. Seuss presents may not fully be the rea l story. Targeting contradictions in his work that do not account for discriminative practice affecting many people of color who suffer from reading disabilities and literacy skills. Through the perspective of Dr. Seuss push towards increasing reading levels and the notion of all it takes is hard work. Concluding this body of work we’llRead MoreAdvantages and Considerations for Wynn Macau’s Casino2526 Words   |  11 PagesExecutive Summary Wynn was among the first 3 concessionaries to enter Macau when its gaming industry was liberated and quickly became one of the most profitable casinos in Macau relative to its size. Junketeers have contributed greatly to wins success, along with government initiatives. Though gambling is illegal in many parts of the world, the industry is growing and competition is increasing, particularly in the east By 2015, the Asian gaming market is expected to be the biggest in the worldRead MoreIdentify And Evaluate Marketing Opportunities BSBMKG501B5284 Words   |  22 Pagesentrepreneurs current business Crown Casino Idea Developed New market Open bet shops in the City Brainstorming New products Poker and Dine in the Crown Casino Brainstorming Turning ideas into business opportunities Virtual Casino with 3-D Glasses Brainstorming Innovate approaches Hostesses who watch out for rookies and show them how to play Brainstomring 25/05/2015 Stefan Frener Potential for new marketing opp. Opens a new market for the Casino which are people who bets on horseracesRead MoreEnron Smartest Guys On The Room1573 Words   |  7 Pagesperspective that holds that criminality is the result of conscious choice and that predicts that individuals choose to commit crime when the benefits outweigh the costs of disobeying the law†(pg 62). For instance, he received many complaints of illegal practices by his trading team, but he refused to take action or discipline them because they making him and the company rich. He even went as far as praising them to continue with their action as long as they are generating more money. Based on Mr. Lay childhood

Recycling of Thermoset Plastics Samples †MyAssignmenthelp.com

Question: Discuss about the Recycling of Thermoset Plastics. Answer: Introduction The article Plastics, Recycling and Technology by the British Plastics Federation illustrates that for a product to be categorized as sustainable, it must fulfill three dimensions aspects related to sustainability. The three conditions include environmental, economical and social aspect of sustainability. They are known as the Three Pillars of Sustainability. Plastics observe the three pillars. Under environmental sustainability, they use a very low percentage of the worlds oil in their production. Plastics are durable and of light weight. This has pushed their usage in planes, phones cars. Their light weight has prompted them to be preferred over other forms of packaging hence saving energy and reducing waste. Cucumbers are covered in plastic to retain their water content as plastics prevent their water loss in moisture form. Plastics play another great role in the construction industry. Plastic foam insulation can be used in making plastic pipes for water, sewerage and electricity purposes. The transport sector also uses plastics. The light weight characteristic entwined with durability makes them even preferable for the sector. They make automobiles light. They are flexible and elastic in that they can be molded into any desired shape for the transport sector. Plastics are also corrosion free. In the aerospace industry, planes bodies such as the Airbus A380 is built from carbon reinforced plastics. This facilitates reduction of fuel consumption as they weigh less. In the article, Plastics Recycling: challenges and opportunities plastics are deemed to be inexpensive and durable. The plastic production is on the increase due to increase in number of uses hence its recycling should be highly encouraged as this reduces oil usage and carbon dioxide emissions. Recycling is a key factor to reduce the wastes available. The recycling depends on the type of plastic materials available. The waste plastic management procedures involved include: Landfill spaces have reduced drastically as land is becoming scarce due to increase in population in the country. This leads to contamination of soil and the underground water The incineration and energy recovery form of waste plastic management is the commonly used one. It has greatly helped in reducing the plastics available in landfills and other waste disposal points. However when plastics are burnt to ashes, they emit fumes which pollute the air. Nonetheless incineration can allow recovery of some energy from the plastics. Down gauging advises business entities and packaging sectors in manufacturing points and industries to reduce the amount of materials used for packaging. It suggests that the amount of packaging materials used should as minimum as possible. This decision has not been welcomed by most of the entities as packaging allows them to promote the product which will improve sales. Customers are attracted by the aesthetic nature of packaging materials when buying a commodity. This has discouraged down gauging making it almost ineffective. Reusing is the plastic packaging is another way of recycling waste plastic management. Reusing can also be described as repurposing. Upon completion of the purpose a plastic was destined for, it can be converted to other purpose where the user feels it can serve effectively and efficiently. However some plastic bags or containers cannot be repurposed or reused. Direct take-back and refilling schemes have been incorporated in several companies so as to reduce plastic wastage available. Plastic recycling has a lot of processes involved. Under this close-loop recycling, tertiary recycling also known as chemical recycling or feedstock recycling are applied. The ideas presented in the articles are effective and efficient in managing waste plastics not only in their respective countries but also worldwide. All these processes allow recycling of waste but none of them illustrates on how part of the non-recyclable plastics can be made biodegradable or recyclable. These plastics are known as thermoset plastics as stated by Seliger (2011). The first article illustrates the diversity of plastic uses and how the plastics conquer the pillars of sustainability. The thermoset plastic formerly they did not observe the three pillars as the option of environmental sustainability was not attained. The article generalizes recycling as if it is the processes involved are applicable to all plastics. It does not categorize plastics as different plastics are used for different purposes. The plastics used in the construction industry differ from those used in planes. One sector will require denser and durable products while the other will require simple and lighter plastics. This report will outline the recycling process of the category of plastics which have not been easily recyclable or repurposed. It will also describe the achievements to be achieved if these plastics are recycled. Body Technology is the greatest factor of evolution in the current world. The National institute of industrial research in India states that technology has fundamentally rearranged our lives from how we do our communication to how we treat patients and also travel. Most of the new technologies have great breakthrough promises of solving worlds most pressing matters ranging from globalization to pollution. Just a glimpse of the power of innovation through technology, one will understand how the ideas will transform industries and safeguard our perishing planet (Tolinski 2012). Waste disposal is a great problem worldwide. It poses significant threat to the environment and the society at large. Apart from eroding the aesthetic value of land they can facilitate survival of disease causing germs. Plastics form a large portion of this waste. This is because they are immensely used in our society for various day to day activities and take time to decompose. Even though some of this waste can be recycled, reused or repurposed to make new product, others cannot be recycled. Plastics are part and parcel of the waste (Eiri Board of Consultants Engineers 2008 p.12). Plastics are a common material in the modern life where their usage is well diversified. Their characteristics that make them preferable such as durability, their lightness in terms of weight and low costs also makes them an environmental menace as they are non biodegradable in nature. Some of the plastics form part and parcel of the non-recyclable waste. Even when they are incinerated the fumes they emit are air pollutants, a phenomenon that every environment conserver will want to avoid (Goodman et.al 2014). Plastics are generally categorized into two. The two categories entail thermo plastics and thermosets. Thermo plastics are those plastics that can be recycled, reused or repurposed. If there is need for them to be recycled a process known as pyrolysis is involved (Alexander et.al 2012). The process transforms plastics back to their original form which is the crude oil where they can be converted into usable fuel. The above articles processes and explanation are well applicable to this form of plastics. Hung et.al (2014) and Goodship (2007) emphasize that Thermoset plastics can only be heated and shaped once, after which they cannot be recycled back, hence retaining their shape and strength even when the heat and pressure is intensified. Due to this characteristic, the thermoset plastics are used in making parts belonging to airplanes, tires, cars, part of medical equipments, mobile phone casings, circuit boards and others this facilitates their large quantity production. The plastics occupy a large portion of the chunks that fill our environment and even water bodies. However, in relation to Alexander (2015) technological advancements have divulged into the waste recycling sector leading to the development of fully recyclable thermoset plastics which can replace the non-recyclable ones. If the new plastic product is proven fit for use, it will be better and cheaper to use. This new plastic is known as polyhexahydrotriazine (PHTs). This type of plastic can be dissolved in strong acids breaking it into component monomers which can be later reassembled to make new products or it can be melted and reshaped into other useful products. These PHTs will help in achieving a sustainable environment and reduce landfill waste (Yam 2009). Researchers have come up with a solution by creating two thermosetting polymers. Polyhexahydritriazine (PHTs) is one of the discoveries. The plastic has an added advantage of durability when carbon nanotubes are added to it. In the process of carrying out the PHTs research, a gel has been discovered which, when used on plastics, gives damaged plastics the ability to heal themselves. This process is known as elastic organogel. (Letcher et.al 2012, Andersen et.al 2015: Gaurina 2015) The PHT will lead to increase the source of sustainable raw materials to the industry. It will also reduce environmental impacts brought about by the numerous products that use plastics. The discovery will reduce the utilization of oil stocks as much of plastics will be recycled. Apart from the above, other achievements expected include: Improving resource efficiency and enable closed-loop material flows. It will give organization easy time to concentrate on innovating products and process. Most industries and manufacturing firms have taken a lot of time and effort in researching for ways of producing recyclable plastics at the same time maintaining their characteristics that suit them best for their functions (Curran 2008). This has led to dedicating massive resources for the same. The discoveries of PHT will ease the budgets and concentrate on serving clients with environmentally sustainable products for their use. According to Alexander et.al (2012) The new thermoset is less expensive than the current alternatives under use which are non-biodegradable and expensive. Incorporation of PHT into use will not be as costly as the current non-biodegradable thermoset polymers. This can lower budgetary strain on the entities or manufacturers who want to use them. Unruh outlines that the new thermoset are also flexible and elastic in that they utilize materials that are already available in the industry. Installing the new polymers doesnt require any changes in the current to the existing compounds and synthetic methods as it can be easily and quickly adopted by the industry (Unruh 2010). The thermoset will solve the demanding situation of recycling ability of the old hardware available. Conclusion In conclusion, recycling is a significant way of ending plastic waste landfill eyesore and managing waste. Through reduction of these materials on the earths surface thanks to the introduction of recyclable thermo sets we will be walking towards sustainability. Recyclable plastic wastes can be converted into other useful plastic based products, thus reducing the hazard caused by plastic waste on the environment and on people(Wolf 2012; Denbratti et.al 2015). More funds should be directed by both the country and individual companies to bring out enhance utilization of these plastics. References ALEXANDER, C., RENO, J. (2012). Economies of recycling: the global transformation of materials, values and social relations. London, Zed Books. https://public.eblib.com/choice/publicfullrecord.aspx?p=992938. ANDERSEN, L., WEIDLING, A., NEIDEL, T. L. (2015). Plastic sorting at recycling centres Background report. Copenhagen K, Nordic Council of Ministers. ANDRADY, A. L. (2015). Plastics and Environmental Sustainability. CURRAN, R. (2008). Collaborative Product and Service Life Cycle Management for a Sustainable World. London, Springer-Verlag London Ltd. Available online at: https://public.eblib.com/choice/publicfullrecord.aspx?p=364102. EIRI BOARD OF CONSULTANTS ENGINEERS. (2008). Plastic waste recycling technology. Delhi, India, Engineers India Research Institute. GAURINA-MEDJIMUREC, N. (2015). Handbook of research on advancements in environmental engineering. https://search.ebscohost.com/login.aspx?direct=truescope=sitedb=nlebkdb=nlabkAN=945915. GODSEY, L. (2013). Interior design: materials and specifications. Pg 229 GOODMAN, S. H., HANNA, D. (2014). Handbook of thermoset plastics. San Diego, William Andrew. Available online at: https://www.books24x7.com/marc.aspx?bookid=58849. GOODSHIP, V. (2007). Introduction to plastics recycling. Shawbury, UK, Smithers Rapra. HUNG, Y.-T., WANG, L. K., SHAMMAS, N. K. (2014). Handbook of environment waste management. INTERNATIONAL CONFERENCE ON SUSTAINABLE AUTOMOTIVE TECHNOLOGIES, DENBRATT, I., SUBIC, A. J., WELLNITZ, J. (2015). Sustainable automotive technologies 2014: proceedings of the 6th ICSAT. https://public.eblib.com/choice/publicfullrecord.aspx?p=2095866. LETCHER, T. M., SCOTT, J. L. (2012). Materials for a sustainable future. Cambridge, UK, RSC Pub. NATIONAL INSTITUTE OF INDUSTRIAL RESEARCH (INDIA). (2007). Hand book on biodegradable plastics: eco-friendly plastics. Delhi, India, Publication Division, National Institute of Industrial Research. SELIGER, G., KHRAISHEH, M. M., JAWAHIR, I. (2011). Advances in Sustainable Manufacturing Proceedings of the 8th Global Conference on Sustainable Manufacturing. Berlin, Springer Berlin TOLINSKI, M. (2012). Plastics and sustainability: towards a peaceful coexistence between bio-based and fossil fuel-based plastics. Hoboken, N.J., John Wiley Sons. https://public.eblib.com/choice/publicfullrecord.aspx?p=818539. UNRUH, G. (2010). Earth, Inc.: using nature's rules to build sustainable profits. WOLF, R. A. (2012). Atmospheric Pressure Plasma for Surface Modification. New York, NY, John Wiley Sons. https://nbn-resolving.de/urn:nbn:de:101:1-201502137113. YAM, K. L. (2009). The Wiley encyclopedia of packaging technology. Hoboken, Wiley.

Paul Tillich Response to Modern Criticism free essay sample

This course explores the themes of Paul Tillichs philosophical theology, with special attention to his analysis of meaning and its apparent loss in modern society. The course will also evaluate Tillichs response to the problem of meaninglessness and his effort to interpret the Christian message. WHAT IS EMPIRICISM? According to John Scott Gordon Marshall, empiricism, in philosophy, is â€Å"the attitude that beliefs are to be accepted and acted upon only if they first have been confirmed by actual experience†. This broad definition accords with the derivation of the name from the Greek word empeiria, meaning â€Å"experience. † Primarily, and in its psychological application, the term signifies the theory that the phenomena of consciousness are simply the product of sensuous experience, i. e. of sensations variously associated and arranged (Andrew M. Colman: 2003:242). It is thus distinguished from Nativism or Innatism. Secondarily, and in its logical (epistemological) usage, it designates the theory that all human knowledge is derived exclusively from experience, the latter term meaning, either explicitly or implicitly, external sense-percepts and internal representations and inferences exclusive of any superorganic (immaterial) intellectual factor. Empiricism is thus opposed to the claims of authority, intuition, imaginative conjecture, and abstract, theoretical, or systematic reasoning as sources of reliable belief. Its most fundamental antithesis is with the latter (i. e. with Rationalism, also called intellectualism or apriorism). Forms of Empiricism According to Catholic Encyclopedia empiricism appears in the history of philosophy in three principal forms: (1) Materialism, (2) Sensism, and (3) Positivism. a. Materialism: Materialism in its crudest shape was taught by the ancient atomists (Democritus, Leucippus, Epicurus, Lucretius), who, reducing the sum of all reality to atoms and motion, taught that experience, whereof they held knowledge to be constituted, is generated by images reflected from material objects through the sensory organs into the soul. The soul, a mere complexus of the finest atoms, perceives not the objects but their effluent images. With modern materialists (Helvetius, dHolbach, Diderot, Feuerbach, Moleschott, Buchner, Vogt, etc. ), knowledge is accounted for either by cerebral secretion or by motion. b. Sensism: All materialists are of course sensists. Though the converse is not the case, nevertheless, by denying any essential difference between sensations and ideas (intellectual states), sensism logically involves materialism. Sensism, which is found with Empedocles and Protagoras amongst the ancients, was given its first systematic form by Locke (d. 1704), though Bacon (d. 1626) and Hobbes (d. 1679) had prepared the data. Locke derives all simple ideas from external experience (sensations), all compound ideas (modes, substances, relations) from internal experience (reflection). Substance and cause are simply associations of subjective phenomena; universal ideas are mere mental figments. Locke admits the existence, though he denies the demonstrability, in man of an immaterial and immortal principle, the soul. Berkeley (d. 1753), accepting the teaching of Locke that ideas are only transfigured sensations, subjectivizes not only the sensible or secondary qualities of matter as his predecessor had done, but also the primary qualities which Locke held to be objective. Berkeley denies the objective basis of universal ideas and indeed of the whole material universe. The reality of things he places in their being perceived and this perceivedness is effected in the mind by God, not by the object or subject. He still retains the substance-reality of the human soul and of spirits generally, God included. Hume (d. 1776) agrees with his two empiricist predecessors in teaching that the mind knows only its own subjective organic impressions, whereof ideas are but the images. The supersensible is therefore unknowable; the principle of causality is resolved into a mere feeling of successiveness of phenomena; its necessity is reduced to a subjective feeling resulting from uniform association experienced in consciousness, and the spiritual essence or substantial being of the soul is dissipated into a series of conscious states. Lockes sensism was taken up by Condillac (d. 780), who eliminated entirely the subjective factor (Lockes reflection) and sought to explain all cognitional states by a mere mechanical, passive transformation of external sensations. The French sensist retained the spiritual soul, but his followers disposed of it as Hume had done with the Berkeleian soul relic. The Herbartians confound the image with the idea, nor does Wundt make a clear distinction between primitive con cepts (empirische Begriffe, representations of individual objects) and the image: Denken ist Phantasieren in Begriffen und Phantasierenist Denken in Bildern. c. Positivism: Positivists, following Comte (d. 857), do not deny the supersensible; they declare it unknowable; the one source of cognition, they claim, is sense-experience, experiment, and induction from phenomena. John Stuart Mill (d. 1870), following Hume, reduces all knowledge to series of conscious states linked by empirical associations and enlarged by inductive processes. The mind has no certitude of an external world, but only of a permanent possibility of sensations and antecedent and anticipated feelings. Spencer (d. 1903) makes all knowledge relative. The actual existence of things is their persistence in consciousness. Consciousness contains only subjective feelings. The relative supposes the absolute, but the latter is unknowable to us; it is the object of faith and religion (Agnosticism). All things, mind included, have resulted from a cosmical process of mechanical evolution wherein they are still involved; hence all concepts and principles are in a continuous flux. d. Classical Empiricism: Classical empiricism is characterised by a rejection of innate, in-born knowledge or concepts. John Locke, well known as an empiricist, wrote of the mind being a tabula rasa, a â€Å"blank slate†, when we enter the world. At birth we know nothing; it is only subsequently that the mind is furnished with information by experience. e. Radical Empiricism: This was advanced by William James, an American pragmatist philosopher and psychologist, based on the pragmatic theory of truth and the principle of pure experience, which contends that the relations between things are at least as real as the things themselves, that their function is real, and that no hidden substrata are necessary to account for the various clashes and coherences of the world. James summarized the theory as consisting of (1) a postulate: â€Å"The only things that shall be debatable among philosophers shall be things definable in terms drawn from experience†; (2) a factual statement: â€Å"The relations between things, conjunctive as well as disjunctive, are just as much matters of direct particular experience, neither more so nor less so, than the things themselves,† which serves to distinguish radical empiricism from the empiricism of the Scottish philosopher David Hume; and (3) a generalized conclusion: â€Å"The parts of experience hold together from next to next by relations that are themselves parts of experience. The directly apprehended universe needs, in short, no extraneous transempirical connective support, but possesses in its own right a concatenated or continuous structure. † The result of this theory of knowledge is a metaphysics that refutes the rationalist belief in a being that transcends experience, which gives unity to the world. According to James there is no logical connection between radical empiricism and pragmatism. One may reject radical empiricism and continue to be a pragmatist. Jamess studies in radical empiricism were published posthumously as Essays in Radical Empiricism (1912). According to him, it is only if it is possible to empirically test a claim that the claim has meaning. As all of our information comes from our senses, it is impossible for us to talk about that which we have not experienced. Statements that are not tied to our experiences are therefore meaningless. This principle, which was associated with a now unpopular position called logical positivism, renders religious and ethical claims literally nonsensical. No observations could confirm religious or ethical claims, therefore those claims are meaningless.