Rhetorical functions in academic writing: Comparison and contrast

Three personal computers, the Evesham Axis 1.33 SK, the Armani R850 P4 and the Mesh Elite 1.7 GT Pro, were compared with respect to the following factors: price, processor speed and size of hard disk. The Evesham Axis, which costs £1,174, is by far the cheapest of the three, the Armani and the Mesh Elite costing £2,467 and £1,938 respectively. The Evesham Axis has the same hard disk size as the Armani, 40 MB, whereas the Mesh Elite is the largest at 57 GB. Regarding the processor speed, the Armani and the Mesh Elite are similar - the processor speed, at 1.7 GHz, being 0.37 GHz faster than the Evesham Axis.

Tribes differed in their basic ways of providing for themselves. Indians of the Southwest lived in villages and planted their corn and squash in orderly rows. However, around the Great Lakes forest Indians hunted deer and small furbearing animals. On the Great Plains braves tracked the buffalo, while in the Pacific Northwest plentiful supplies of salmon and other fish tempted Indians into their canoes and kept hunger away.

Bernard Weisberger, The impact of our past. McGraw Hill, 1972.

Marx referred throughout his work to other systems than the capitalist system, especially those which he knew from the history of Europe to have preceded capitalism; systems such as feudalism, where the relation of production was characterized by the personal relation of the feudal lord and his serf and a relation of subordination which came from the lord's control of the land. Similarly, Marx was interested in slavery and in the classical Indian and Chinese social systems, or in those systems where the ties of local community are all important.

In the 19th century, two widely differing schools of socialist thought emerged, the Utopian Socialists and the Marxians. The first group believed that public ownership of the means of production was a necessary goal for human happiness. However, they wanted to reach it gradually and peacefully, using democratic methods to make changes through the government. They believed in ballots, rather than bullets. They also felt that owners who had mines, factories or land taken away by the government should be paid for their property. People who have these beliefs today are called Socialists. The second group, led by Marx, also wanted the government to take over all private property used to produce goods. However, their methods were to be very different. They thought that violence or revolution would be necessary because the owners of property would fight to hold on to it. No payment should be made to these owners who lost their property. Today, those who believe in these methods are called Communists.

Edward Kolevzon, The Afro-Asian world. Allyn & Bacon, 1971.

Both Bachofen and Morgan believed that, since you belonged to the group by virtue of being your mother's son, women in such a system must have a particularly high status. Engels, however, does not completely follow Bachofen in the belief that at this stage women were actually superior to men.

As a first step in describing this debate, consider the positions taken up by the two leading naturalists at the end of the eighteenth century, the Swede Linnaeus and the Frenchman Buffon. Although both men were forced to modify their opinions later in life, initially they held the extreme 'nominalist' and 'essentialist' positions. Buffon held that only individuals are real. We group them into species merely as a convenience; if we did not do so, we could not give them names: hence 'nominalism'. For Linnaeus, in contrast, each species had its own essential characteristics - its essence; individual members of a species may differ, but only in non-essential ways.

Belief in the cyclical nature of the universe found its apotheosis in the concept of the Great Year, which the Greeks may have inherited from the Babylonians. The idea had two distinct interpretations. On the one hand, it was simply the period required for the sun, moon, and planets to attain the same positions in relation to each other as they had at a given time. This appears to be the sense in which Plato used the idea in the Timaeus . On the other hand, for Heraclitus it signified the period of the world from its formation to its destruction and rebirth.

Locke's distinction between the real and nominal essence of substances is brought out nicely by his analogy of the Strasburg Cathedral clock. Locke's contemporaries marvelled at this human creation just as they marvelled at nature as seen through the microscope. The clock did a lot more besides telling the time of day. For example, it incorporated a globe of the heavens with a revolving sun and moon, an astrolabe showing the positions of the planets, statues which sounded bells, and a mechanical cock. Gassendi spoke of our not knowing the corpuscular nature of things, the 'inner shrines' of nature, but only their appearances; similarly, the 'gazing countryman', as Locke calls him, would know only the clock's outer show, and not its internal mechanism. The 'nominal essence' of the clock is the idea we have of it and, as with gold, this will vary from person to person. One observer may have been particularly impressed by the figure of Death sounding the hours on a bell, and his idea will include that. Another, who did not pass by on the hour, might think, not of Death, but of the astrolabe showing the positions of the planets. Though different in detail, these ideas are similar, in that they both derive from the clock's observable characteristics and behaviour. For Conrad Dasypodius, however, the mathematician at Strasburg Academy who designed and planned the clock, the nominal essence would be radically different. He would understand in detail the working of the mechanism of the clock, which enables it to function as it does. His general idea, his 'nominal essence' of the clock would be an idea of what is, in effect, its 'real essence'.This work of art provided an analogy for works of nature such as gold. They both have observable features and properties. The clock has moving hands and figures; gold is yellow, malleable, soluble in some acids, and not in others. Then, just as the clock, and clocks like it, have a certain inner mechanical constitution from which these features arise, so has gold in the view of those who adopted the corpuscular hypothesis. The different performances of other clocks correspond to different mechanisms; the differences in quality of different substances, the yellowness of gold, or the silvery colour of lead, similarly correspond to differences in the shape, size, arrangement, and state of motion of their corpuscles.

But there is an important difference between the clock, which is what Locke calls an 'artificial substance', and naturally occurring substances such as gold. The clock's designer would know the details of its real essence whereas, says Locke, none of us know the real essence of gold. Our sensory capacities are too limited.