1.Was the British Empire a force for good Essay

1.Was the British Empire a force for good - Essay Example nostalgia for a more civilized and benign Greater Britain through television programs, such as, This Sceptred Isle and Empire’s Children, while print critics openly condemn it as a blood-stained autocracy (Brendon, 2007). Historian Lawrence James argues, ‘ploughing a familiar furrow,’ but we should always be proud of the Empire that established stability, progress, and beneficial institutions in colonies. In this research paper, I tried to define British Empire’s role as good or bad and conclude that it was neither good nor bad, but complicated. One must argue that why there is controversy about it. Mainly, vast range of British Empire and its lasting impact epitomizes a period in which all of the non-Europeans were dominated by Europeans. Another reason for controversy about Empire is its vastness that defies simple summary, and therefore, perspectives on it also vary outrageously. It is possible for Empire’s admirers or opponents to pick some examples in order to prove that British rule, by and large, was good or bad, and its legacies as beneficent or demonic. Some assert that it was an engine of modernization, while others believe that it was a vehicle of exploitation (Jackson, 2013, p.4). As decolonization of European Empires precipitated in the 1960s, Jean-Paul Sartre wrote that, â€Å"†¦It was nothing but an ideology of lies, a perfect justification for pillage; its honeyed words, its affection of sensibility were only alibis for our aggressions† (cited in Jackson, 2013, p.4) while Niall Ferguson ar gues that British Empire was better than the other empires from the same period. The record of British Empire is not untarnished by any means, but it gave us global trade and the rule of law (cited in Jackson, 2013, p.4). In an effort to explore Empire’s credits, one may lead to the idea that British Empire was a liberal empire. It was established on the principals classically enunciated by Edmund Burke, who asserted that colonial government was a

Using examples, critically discuss the importance of gastronomy to at Essay - 1

Using examples, critically discuss the importance of gastronomy to at festivals - Essay Example In today’s tourism industry, destinations are presenting food as a key element of their package to attract tourists. The objective of this essay is to analyze the role of gastronomy at festivals. A very good example of festival and trade based on gastronomy is Whitstable Oyster Festival in Kent. It is one of the ancient food festivals in the UK (Hall et al, 2008). It celebrates the tradition of the oyster industry in Kent. Haven-Tang et al (2006) have discussed the role of food festival in developing a sense of place. In the context of Monmouthshire food festival, the focus on local food and drink has been reported to have significant positive impact on the local economy Haven-Tang et al (2006). Moreover, it has proved that the emphasis on local food and drink through these festivals improve the visitor experience as well. A very interesting gastronomy project that was customized and exclusively designed for the promotion of local food and community was the ‘Eat the View’ project developed by the UK countryside agency. The festivals as part of this are reported to have created awareness among the travelers on the local food and culture and have had substantial positive influence on the promotion of local food ventures (Hall, 2005). The Great British Food Festival - Staffordshire, The Colchester Food and Drink Festival are some among a lot of food festivals coming up in the UK confirming the increasing role of gastronomy in tourism. Wine festivals are reported to be of great potential in the context of the United Kingdom (Hall et al, 2008). The ‘Taste of London Festival’ which was conducted in Regent Street in the summer of 2007, was a gourmet festival which is reported to have important role in improving awareness among the tourists on British Food. This brand of food festiva l was later replicated in the cities of Bath, Edinburgh, Birmingham and Dublin (Hall et al, 2008). The impact of

Ofdm Techniques In Satellite Communications

Ofdm Techniques In Satellite Communications The concept of Orthogonal Frequency Division Multiplexing was first proposed in 1960 and developed in the 70s .All bandpass modulation schemes use single carrier by adjusting frequency, phase or amplitude .As Digital transmission uses high Bandwidth (data rates), the duration of bit information becomes smaller. The system becomes more vulnerable to loss of information from impulse noise,signal reflections and other impairments. As the bandwidth used by a single carrier system, the vulnerability to interference from other continuous signal sources become greater. ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING Modulation:-A mapping of the information on changes in the carrier phase, frequency or amplitude or combination. Multiplexing:-Method of sharing a bandwidth with other independent data channels. OFDM is a combination of both multiplexing and modulation. OFDM is a special case of FDM . In OFDM the signal is first split into independent carriers, modulated by data and then re-multiplexed to create a OFDM carrier. This can be done by using different modulation/demodulation techniques. The FDM systems requires a guard band between modulated subcarriers to prevent the spectrum of one subcarrier from interfering with another and not using bandwidth efficiently as in fig(i). If the FDM system uses a set of subcarriers that are orthogonal to each other. The use of orthogonal subcarriers would allow the subcarriers spectra to overlap,thus increasing spectral efficiency. As long as orthogonality is maintained, it is possible to recover the individual subcarriers signals despite their overlapping spectrums. . Fig(1): General representation of an FDM scheme with guard bands. Fig(2): Orthogonal FDM, eliminating the guard bands. OFDM can be implemented using the Discrete Fourier Transform (DFT). The sinusoids of the DFT form an orthogonal basis set, and a signal in the vector space of the DFT can be represented as a linear combination of the orthogonal sinusoids. One view of the DFT is that the transform essentially correlates its input signal with each of the sinusoidal basis functions. The OFDM signal can be a baseband signal or a band pass signal. For wired systems, due to the limited bandwidth of the wires, baseband OFDM signals are transmitted. For wireless communications, such as wireless local area network (WLAN) specified by IEEE 802.11a standard OFDM signal frequency bands are allocated in the RF frequency band. In this case, OFDM signals are generated in baseband first and up-converted to the RF band for transmission. Mathematically, the OFDM signal using the DFT/IDFT pair would be as shown [4]: DFT: X(k)=ÃŽ £n=0to(N-1) x(n) exp(-j2Ï€nk/N) IDFT: x(k)=(1/N) ÃŽ £n=0to(N-1) X(n) exp(j2Ï€nk/N) Figure (3): General block diagram of OFDM MULTIPATH CARRIERS As OFDM uses Multipath carriers they cause two problems Intersymbol Interference:-This occurs when the received OFDM is distorted by the previously transmitted OFDM symbol.Where as in single carrier the interfere is due to several other symbols instead of just the previous symbol. Intersymbol Interference can be removed by using guard interval. Intrasymbol Interference:-This occurs due to the interference amongst a given OFDM symbols own subcarriers. Fig(4): Performance evaluation of various modulation techniques with OFDM OFDM ADVANTAGES AND DISADVANTAGES OFDM offers many advantages over single-carrier modulations [1]: The maximum signaling rate (Nyquist rate) for a given channel can be approached without the use of sharp cutoff filters. It elongates the symbol period so that the signal is more robust against inter symbol interference caused by channel dispersions and multipath interference. It divides the entire frequency band into narrow bands so that it is less sensitive to wide-band impulse noise and fast channel fades. The effect of a slow frequency-selective fade is a separate complex gain on each sub-band signal and it can be removed by simply multiplying the signal by the conjugate of the complex gain-that is, equalization can be easily done by a one-tap equalizer. Different modulation formats and data rates can be used on different subcarriers depending on the noise level of individual sub-bands (the symbol periods are kept the same). In serial transmission, certain types of noise (such as time varying tone interference) may cause an entire system to fail; the parallel OFDM system can avoid this problem by adaptively reducing the data rate of the affected sub-bands or dropping them. OFDM can be implemented digitally using an inverse discrete Fourier transform and discrete Fourier transform (IDFT/DFT) pair (via the efficient fast algorithm IFFT/FFT pair), which greatly reduces the system complexity. OFDM is based on a parallel data transmission scheme that reduces the effect of multipath fading and makes the use of complex equalizers unnecessary. OFDM achieves high spectral efficiency by allowing the sub-carriers to overlap in the frequency domain. The sub-carriers are made orthogonal to each other therefore there is no Inter-Carrier Interference. If the number of sub-carriers in N, the total bandwidth required is BWtotal=(N+1)/Ts. For large values of N, the total bandwidth required can be approximated as BWtotal=(N)/Ts. On the other hand, the bandwidth required for single carrier transmission of the same data is BWtotal=(2N)/Ts. Thus we achieve a spectral gain of nearly 100% in OFDM compared to the single carrier transmission case. OFDM also have DISADVANTAGES over single carrier modulation systems The OFDM signal has a noise like amplitude with a very large dynamic range, therefore it requires RF power amplifiers with a high peak to average power ratio. It is more sensitive to carrier frequency offset and drift than single carrier systems are due to leakage of the DFT. High sensitivity to synchronization errors. Nonlinear effects generated by the power amplifier may introduce inter carrier interference and thus destroy the orthogonality. Larger sidelobes may result in sensitivity to frequency. APPLICATIONS OF OFDM Wireless LAN Applications HIPERLAN/2 HIPERLAN/2 is a Wireless LAN application defined by the ETSI. HIPERLAN/2 handles data rates between 6-54 Mbit/s. HIPERLAN/2 provides a DLC layer on top of which an IP based broadband network can be implemented. The Physical layer of HIPERLAN/2 is based on the Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme. The Numerical Values of OFDM parameters in HIPERLAN are given below: Parameter Value Sampling rate fs=1/T 20 MHz Symbol part duration TU 64*T 3,2  µs Cyclic prefix duration TCP 16*T, 0,8  µs (mandatory); 8*T, 0,4  µs (optional) Symbol interval TS 80*T, 4,0  µs (TU+TCP) ; 72*T, 3,6  µs (TU+TCP) Number of data sub-carriers NSD 48 Number of pilot sub-carriers NSP 4 Sub-carrier spacing à ¯Ã‚ Ã¢â‚¬Å¾f 0.3125 MHz (1/TU) Spacing between the two outmost sub-carriers 16.25 MHz (NST*à ¯Ã‚ Ã¢â‚¬Å¾f) IEEE 802.11 The IEEE 802.11 committee has a standard similar to the HIPERLAN. Its OFDM parameters are as shown below: Data Rate 6,9,12,18,24,36,48,54 Mbps Modulation BPSK, QPSK, 16-QAM, 64 QAM Coding Rate 1/2, 2/3,3/4 No of Sub-Carriers 52 No of pilots 4 OFDM Symbol Duration 4 us Guard Interval 800 ns Sub-Carrier Spacing 312.5 kHz 3 dB bandwidth 16.56 MHz Channel Spacing 20 MHz Satellite Communication applications Digital Audio Broadcasting (DAB) Digital Audio Broadcasting is a new multimedia technology, with a good sound quality and better spectrum efficiency. The DAB system samples audio at a sample rate of 48 kHz and a resolution of 22 bits. Then the data is compressed to between 32 and 384 kbps. A rate  ¼ convolution code is used with constraint length 7. The total data rate is about 2.2 Mbps. The frame time is 24ms. QPSK modulation is performed at the transmitter. The advantage of using OFDM for DAB is that the OFDM suffers very little delay spread and has high spectral efficiency. Digital Video Broadcasting (DVB-T) Digital Video Broadcasting is an ETSI standard for broadcasting Digital Television over satellites, cables and through terrestrial (wireless) transmission. Terrestrial DVB operates in either of 2 modes called 2k and 8k modes with 1705 carriers and 6817 carriers respectively. It uses QPSK, 16-QAM or 64-QAM subcarrier modulations. It also uses pilot subcarrier for recovering amplitude and phase for coherent demodulation The major use of OFDM can be observed when multiple techniques can be transmitted and received at the same time. This can be done with the help of MIMO OFDM. The transmitted signal will be received by various VSAT networks based on the corresponding frequencies. Further, processing of this signal and error corrections, the original signal is retrieved. For example, consider that a DAB, DVB and other geological information is received by various antennas as shown in the figure. NEWEST RESEARCH AND FUTURE TRENDS OF OFDM One of the methods developed in the recent years is that the convolutional coding (CC) and trellis coded modulation (TCM) are combined with OFDM for a Rician fading channel according to the specifications given by the Iridium system. Here, the bit error rate (BER) performance of OFDM with 8-PSK and 16-QAM modulation techniques along with two different coding schemes are considered for a LEO satellite channel. Trellis coded OFDM gives the best performance compared to convolutional coded OFDM. The peak to average power ratio (PAPR) can be reduced approximately by 1.5 dB with the help of the partial transmit sequence technique (PTS). Later, some more research and simulation results proved that the Turbo Coded (TC) OFDM performed better than CC or TCM with OFDM [6]. Satellite mobile systems are developed to provide connectivity between remote terrestrial networks, direct network access, Internet services using fixed or mobile terminals, interactive multimedia applications, and high data-rate transmissions. Most of these research and development scenarios have considered the Non-Geo Stationary Satellite (NGSO) network for providing satellite-based mobile multimedia services because of its low propagation delay and low path loss. As a result, new generations of broadband satellite communication systems are currently being developed to support multimedia and Internet-based applications. For example, the Spaceway system provides downlink transmission rates of up to 100 Mbps, and a total capacity of up to 4.4 Gbps. In order to significantly increase the capacity of 4G broadband satellite systems, current research aims at developing new advanced technologies [5]. In the wireless system, OFDM is the main basis for several television and radio broadcast applications, including the European digital audio broadcasting (DAB) and high-definition TV (HDTV) terrestrial broadcasting as well as North American digital radio broadcasting. By the beginning of the 21st century, OFDM has been adopted as standard for new high-rate wireless local area network (WLAN), such as IEEE 802.11, HIPERLAN II, as well as the Japanese Multimedia Mobile Access Communications (MMAC). Currently, many researches are underway to devolve an OFDM-based system to deliver mobile broadband data service at data rates comparable to those of wired services, such as DSL and cable modems. Moreover, OFDM technology is a very attractive candidate when targeting high quality and high flexibility in mobile multimedia communications over satellite systems [6]. When the research interest is in the integration process of 3G terrestrial systems with the satellite domain, the conventional frequency division MAS (FDMA) system looses its flavor in competing with the code division MAS (CDMA) and time division MAS (TDMA)-based systems for its very high bandwidth (BW) requirement. Moreover, in satellite systems, it is shown that CDMA system outperforms the FDMA system when diversity is taken in to account. In this case, OFDM replaces FDMA with manifold advantages. Currently wideband CDMA (W-CDMA) and OFDM/TDMA techniques are successfully in use in terrestrial mobile multimedia systems. Therefore, these two Multiple Access schemes (MASs) are getting considerable attention [7] in mobile multimedia communications for Non-Geo Stationary Satellite interface.

Philistinism In England And America :: essays research papers

Comments on Matthew Arnold’s "Philistinism in England and America" In his essay, "Philistinism in England and America," Matthew Arnold examines the ancient ideas of Plato in the context of a twentieth century, capitalist society. As he agrees with almost all of what Plato had to say, he also admits that he is outdated, and that some of his teachings cannot be applied to us, living in an industrial superpower such as the United States. Still, though, Arnold defends the ancient philosopher. Education as a route to mental and physical righteousness is always a good idea, whether it is in modern America or Ancient Greece. I disagree with this, and it is here that I must contest the writings of Plato, as well as the essay by Arnold, for he is definitely a strong backer of the ancient ideals. In Plato’s mind, the value of an education is to clear one’s mind of impure thought, bring it to a higher lever than at the start, and attain a certain level of righteousness. This may have been a good idea 2300 years ago, but today, I see it as very limiting and impractical. In his time, only the rich aristocrats went to school. It’s purpose was not for the students to learn skills or ideas that would help them later in life, but to expand their minds, thus making them into ‘better people.’ There was no need for them to learn any job skills. Back then, if you came from a rich family, you were rich. Working at simple jobs was for the peasants and slaves. Today, life is different. Our society is completely unlike that of the ancient Greeks. We have no caste system limiting the wealth and prominence of any citizen, we have no slavery to handle all the manual labor, our army is proportionately smaller and much less honored, and religion is a part of one’s private life, not a dominating public force as it was to the Ancient Greeks. Most people today have a regular, day to day job, whether it be in an office, store, factory, or anywhere else. We have to earn our wealth by working, not inheritance. That is why most people go to school today. I am attending NYU so that I can get a job later in life. I study chemistry and engineering, in the hopes that I can become a chemical engineer.

Job Application Letter

I-2-10 Blok 1 Lorong Sierra Apartment PH I/3A Jalan Tuaran Menggatal 88450 Kota Kinabalu, Sabah October 4, 2012 Ms Alicesia Yong IEC Group 987 Lorong Jering 2 Sunny Garden Mile 1. 5 Tuaran Road 88300 Kota Kinabalu, Sabah Dear Ms Alicesia I am writing in response to your advertisement in the JobStreet. com dated 2 October 2012. I am interested for applying the position of Administration Officer in your company. I am a fresh graduate from University Malaysia Sarawak with Human Resource Development’s bachelor degree.I am applying this position because the position requirements and my skills are a perfect match. During my studies in university I am being exposed to human resource roles in an organisation. I am trained with skills in handling administrative work not only for in managing people but also for documents. Beside that, neuroscience and human development phycology course which I have taken gave me advantages in understanding people better based on their ages and also pers onality.In addition, I have done some research in Institut Tabiran Awan Negara (INTAN) in purpose of making my self familiar working condition in managing people effectively in terms of training and development. Outcome of this research, I leaned skills in interaction with people and get chance to do events for the worker for dinner party and I received such a good complement by my managers. I would like to continue and develop my skills and knowledge in your company. I have worked on my communication skills in English during this event. I can promise that meeting with me will not be a waste of time.I can be contacted via email at [email  protected] com or my phone number 0168447028. I look forward to receiving reply from your company soon and I will be available to interview in start from 10 October until 20 October this year. Thank you. Sincerely Cheryl E. Gitom Encl. : Resume CHERYL E. GITOM I-2-10 Blok 1 Lorong Sierra Apartment PH I/3A Jalan Tuaran Menggatal 88450 Kota Kinabal u, Sabah ————————————————- 0168447028 Human Resource Education Bachelor of Science Degree in Human Resource Development, October 2011, University Malaysia Sarawak.Objective To help and assist administrative work and marketing activities IEC (School of English Language and Further Counselling Services) in an effective way. Management Skills Office skills * Office management, records management and also database administration. * Capable in event management and calendaring. * Clearly understand in documentation progress. Computer skills * Able to use Microsoft Offices such as Word and Publisher and analytic software, IBM SPSS. * Able to do web designing using Dreamweaver and FrontPage. Social skills Communicated effectively with departments to plan meeting and able to prepare event. * Help in coordinate recruitment events with high level standard. * Fluency in speaking Malay and English Language. Experiences Managing Christmas Event * Developing innovative PowerPoint presentation used by the Event Manager to market our company to outsider. * Helped the accounting section to monitor their expanses. * Communicated with other companies to raise some fund. * Entrusted by the leader to handle such a big money and ticketing issues. * Earned excellent marks for being the top seller for the event’s tickets.Involve in Management Research (Institut Tabiran Awam) * Working in group team to observe management of training for new recruits. * Created schedule and manage time for the training programme. * Recommended specific training activities. References Dr Norazila Abdul Aziz Senior Lecturer of  Department of Cognitive Science University Malaysia Sarawak Email:  [email  protected] unimas. my Phone: +6 082 – 581518 Nor Hasniah Ibrahim Lecturer of  Department of  Counselling University Malaysia Sarawak Email:  [email  protected] unimas. my Phone: +6 082 – 581532

What Is the Jet Stream and How It Affects Our Weather

What Is the Jet Stream and How It Affects Our Weather Youve probably heard the words jet stream many times while watching weather forecasts on TV. Thats because the jet stream and its location is key to forecasting where weather systems will travel. Without it, there would be nothing to help steer our daily weather from location to location. Rivers of Rapidly Moving Air Named for their similarity to fast moving jets of water, jet streams are bands of strong winds in the upper levels of the atmosphere. Jet streams form at the boundaries of contrasting air masses. When warm and cold air meet, the difference in their air pressures as a result of their temperature differences (recall that warm air is less dense, and cold air, more dense) causes air to flow from higher pressure (the warm air mass) to lower pressure (the cold air mass), thereby creating high winds. Because the differences in temperature, and therefore, pressure, are very large, so too is the strength of the resulting winds. Jet Stream Location, Speed,Direction Jet streams live at the tropopause (about 6 to 9 miles off  the ground) and are several thousand miles long. Jet stream winds range in speed from 120 to 250 mph, but can reach more than 275 mph. Oftentimes, the jet houses pockets of winds that move faster than the surrounding jet stream winds. These jet streaks play an important role in precipitation and storm formation. (If a jet streak is visually divided into fourths, like a pie, its left front and right rear quadrants are the most favorable for precipitation and storm development. If a weak  low pressure area  passes through either of these locations, it will quickly strengthen into a dangerous storm.) Jet  winds blow from west to east, but also meander north to south in a wave-shaped pattern. These waves and large ripples (known as planetary, or Rossby waves) form U-shaped troughs of low pressure that allow cold air to spill southwards, and upside-down U-shaped ridges of high pressure that bring warm air northwards.  Ã‚   Discovered by Weather Balloons One of the first names associated with the jet stream is Wasaburo Oishi. A Japanese meteorologist, Oishi discovered the jet stream in the 1920s while using weather balloons to track upper level winds near Mount Fuji. However, his work went unnoticed outside of Japan. In 1933, knowledge of the jet stream increased when American aviator Wiley Post began exploring long-distance, high-altitude flight. Despite these discoveries, the term jet stream was not coined until 1939 by German meteorologist Heinrich Seilkopf. Meet the Polar and Subtropical Jets While we typically talk about the jet stream as if there was only one, there are actually two: a polar jet stream and a subtropical jet stream. The Northern Hemisphere and the Southern Hemisphere each have both a polar and a subtropical branch of the jet. The Polar Jet:  In North America, the polar jet is more commonly known as the jet or the mid-latitude jet (so-called because it occurs over the mid-latitudes).The Subtropical Jet:  The subtropical jet is named for its existence at 30 °N and 30 °S latitude- a climate zone known as the subtropics. It forms at the boundary temperature difference between air at mid-latitudes and warmer air near the equator. Unlike the polar jet, the subtropical jet is only present in the wintertime- the only time of year when temperature contrasts in the subtropics are strong enough to form jet winds. The subtropical jet is generally weaker than the polar jet. It is most pronounced over the western Pacific. Jet Position Changes With the Seasons Jet streams change position, location, and strength depending on the season. In the winter, areas in the Northern Hemisphere may get colder than normal periods as the jet stream dips lower bringing cold air in from the polar regions. Although the height of the jet stream is typically 20,000 feet or more, the influences on weather patterns can be substantial as well. High wind speeds can drive and direct storms creating devastating droughts and floods. A shift in the jet stream is a suspect in the causes of the Dust Bowl. In spring, the polar jet starts to journey north from its winter position along the lower third of the U.S., back to its permanent home at 50-60 °N latitude (over Canada). As the jet gradually lifts northward, highs and lows are steered along its path and across the regions where its currently positioned. Why does the jet stream move? Well, jet streams follow the Sun, Earths primary source of heat energy. Recall that in spring in the Northern Hemisphere, the Suns vertical rays go from striking the Tropic of Capricorn (23.5 ° south latitude) to striking more northerly latitudes (until it reaches the Tropic of Cancer, 23.5 ° north latitude, on the summer solstice). As these northerly latitudes warm, the jet stream, which occurs near boundaries of cold and warm air masses, must also shift northward to remain at the opposing edge of warm and cool air. Locating Jets on Weather Maps On surface maps: Many news and media that broadcast weather forecasts show the jet stream as a moving band of arrows across the U.S., but  the jet stream isnt a standard feature of surface analysis maps. Heres an easy way to eyeball the jet position: since it steers high and low pressure systems, simply note where these are located and draw a continuous curved line in-between them, taking care to arch your line over highs and underneath lows. On upper level maps: The jet stream lives at heights of 30,000 to 40,000 feet above Earths surface. At these altitudes, atmospheric pressure equals around 200 to 300 mb; this is why the 200 and 300 mb level upper air charts are typically used for jet stream forecasting. When looking at other upper level maps, the jet position can be guessed by noting where pressure or wind contours are spaced close together.

Descartes Essays - Ren Descartes, Epistemology, Rationalists

Descartes Essays - Ren Descartes, Epistemology, Rationalists Descartes Descartes was a "jack of all trades", making major contributions to the areas of anatomy, cognitive science, optics, mathematics and philosophy. Underlying his methodology is the belief that all science is based on mathematics. This is manifested in his unification of ancient geometry and his new alegbra based on the Cartesian coodinate system. For Descartes, certainty in philosphy and in mathematics is gained through understanding. We may know that two apples and two apples makes four apples, but Descartes believes that matematics transcends the senses, contributing to an overall mathematical order to the universe that is independent of senses. Senses were at the center of his Meditations on First Philosphy, a work in which Descartes explores the concepts of self, God and mind. He begins by shaking our belief in the sneses; if they are all an illusion created by a malicious deceiver, what can we trust? His answer is that we can doubt, and that the deceiver cannot cause us to doubt our own existence. Thus, the famous "cogito ergo sum" (I think therefore I am). However, the I is not a physical "i", is is an immaterial mind that is identified by "I". Thus begins Cartesian Dualism, the theory that there are two fundamental types of entities : mind and matter. The physical bodies exists extended in space, with depth, width and breadth. However, minds are entirely immaterial and nonspatial; they are the "I" he refers to. Since the mind is the only entity that can think (rocks cannot), Descartes uses the cogito arguemnt to prove the existence of a mind.