In order to examine whether or not ‘truth’ and ‘knowledge’ are still tenable concepts, it is necessary to identify exactly what is post-structuralist and postmodernist cultural theory, both in terms of aesthetic and discourse and how that discourse is applied to grand narrative texts to cause this doubt about ‘truth’ and ‘knowledge’ in the modern day. In terms of both discourse and defining characteristics, post-structuralism and postmodernism share some similarities. Also, the two cultural discourses share a similar period of emergence in the 1960’s, when anti-establishment concepts became increasingly popular, especially in such cultural forms as literature and architecture.

Post-modernism is very much a Western phenomenon, and as has been said, emerged to prominence during the 1960’s with such writers as Jean Boudrillard producing works that scrutinised various aspects of the postmoderist aesthetic, including the concept of ‘hyperreality’, where copies of an original mean more than the original itself. Literally meaning "the period after modernism", postmodernism can be interpreted in two possible ways. Firstly, postmodernism can be seen as a continuation or a reinstatement of the search for modernist values such as reason, justice and equality, concepts originating from the Enlightenment and the Age of Reason, where archaic feudalistic discourses which had dominated Europe throughout the Medieval period, were undermined and overthrown in favour a new society with more egalitarian values. However, an alternate view of postmodernism is that it is a reaction to, and break with, traditional modernist values, which have been greatly affected by the events of the 20^th Century. Indeed, some critics would suggest that these modernist values were to blame for such 20^th Century crises as poverty, world war, holocaust and pollution. Postmodernism in the post-war period has caused widespread transformations in Western thought, with emphasis on other, new, aspects of cultural and artistic, as the West moves into and through the post-industrial age, with dominating emphasis on high-technology and mass-consumerism.

As part of the post-industrial age, economic emphasis has moved from supply to demand, and flexibility of production and distribution have become essential in order to fulfil the ever-changing (but not necessarily ever-evolving) desires of the consumer. The breakdown of industrial class barriers has also sent the old class system into a state of flux, and in Britain’s case, the Upper-Middle-Lower-class boundaries cannot be applied to modern society anymore. There are now numerous sub-class divisions, predominantly based on occupation, where the boundaries are much more fluid, and changing in order to adapt to ever-fluctuating tastes of the consumer. This new age, fractured from traditional modernist values, has undermined many of the social and cultural discourses and grand narratives that dominated the previous era. Religion, Marxism and the ‘nuclear’ family have become discarded as dominant social and political discourses, with the disappearance of the Soviet Union, and the Church seemingly increasingly marginalised in the capitalist society of the West. The diminishing of these once-powerful discourses has left a vacuum, which has been filled by the pluralistic views of those areas of society that were marginalised by the grand narratives. Activists, political lobbyists, and moral institutions such as Greenpeace may well have benefited from this change in the attention of society, to the extent that these factions in society are receiving more coverage and are being allowed to communicate with society on a greater scale. Political boundaries are also being clouded, and political roots and history are being are being somewhat discarded, for example, in British politics, New Labour’s move towards the centre ground in order to become more electable for the powerful so-called middle-classes.

With the breakdown of the grand narratives that governed modernist society came the fragmentation of meaning. Symbols and signifiers, that once meant one thing when taken in the context of these grand narratives, no longer mean what they did when taken in the new context. Just as these identities change, and historical roots and meaning are discarded, it follows that theses symbols and signifiers no longer have a source or fixed ideology with which to anchor themselves to and centre upon. Therefore, these floating signifiers are symptomatic of aspects of culture that are unstable, and constantly changing every time a new context is applied to these signifiers. The important notion behind this instability or paucity of meaning is that the texts that formed the basis of the old grand narratives also fall victim to this dissolution of meaning. It could be argued that the texts are now merely pastiches of knowledge, where they have no depth or meaning, because their ‘true’ context has been discarded with the grand narratives back in the modernist era. Indeed, Boudrillard’s work from the late-1980’s and 1990’s would suggest that this ‘disappearance of meaning’ is symptomatic of a ‘progression’ (for want of a better word) to nihilism and anarchy.

Another aspect of postmodernism that has a profound effect on the validity of ‘truth’ and ‘knowledge’ as facets of grand narratives is the concept of omnipotence and impotence in authorship. A prominent feature of postmodernist literature is the presence of an unreliable narrator. In many grand narrative texts such as the Bible, both in Genesis and the Gospel According to St. John, the narrative style is that of an omniscient narrator (or omniscient multiple narrators). The use of omniscient narration gives authority to the text, and communicates trustworthiness, and heightens the feeling that the content of the text must be ‘truth’. However, the use of the unreliable or impotent narrator in postmodernist texts, commonly placing the narrator as part of the narrative, not only gives the text a sense of immediacy and individualism (i.e. ‘this one person’s story’, and a key aspect of postmodernism), but also calls into question what is the truth, and whose truth is it? Texts such as John Fowles’ The French Lieutenant’s Woman, may have multiple endings, which further emphasises that the concept of ‘truth’ may be more subjective than the grand narrative texts would have the reader believe. This of course would explain the multiplicity of ‘truths’ that can be seen in the religions throughout the world, where each denomination of each religion believes in different interpretations of what they believe is the ‘truth’.

Charles Darwin’s The Origin of Species is a model example of an Enlightenment modernist scientific text. It is in this text that Darwin introduces the theory of Natural Selection, and, in The Descent of Man, Man’s evolution from the Apes and the similarities between human behaviour and that of the animals. Of course, this theory directly challenged the belief upheld by the church in the Creation story, and that man was made in the image of God (to rule over the Earth as God’s incarnation), totally undermined the feudal system, and everything that it stood for, such as absolute monarchy and predominance of one man over another. Darwin’s work was attacked from two perspectives: by those who criticised The Origin of Species because it contradicted the literal word of the Bible; and by some of Darwin’s contemporaries in the scientific community who believed that Darwin’s information and research was not reliable or accurate. However, Darwinian theory of evolution has been reinforced in the 20^th Century by the identification of the gene, and the comparison of the human genome to Man’s closest relative, the chimpanzee.

While Darwin’s theory of Man’s evolution from the Apes has been vindicated, his work on Natural Selection has been called into question, based very much on the interaction of the theory, and the expression of the theory, with other discourses that were prevalent in Darwin’s time. Postmodernist theory would argue that Darwin has used contemporary capitalist concepts such as economic competition, adaptation and symbiosis to account for the predominance of some species at the expense of others, and where the male of the species takes precedence in the study, while the female in relegated to a relatively minor role. It could also be said that, in many ways, this interpretation of Natural Selection and the ‘survival of the fittest’ draws remarkable similarities to laissez-faire Victorian society that Darwin’s theories originate from. Postmodernist theory would also highlight the way in which Darwin’s theories are communicated, using a literary style drawn from Enlightenment writers. Essentially, therefore, not only does Darwin’s work bear parallels (and therefore seem influenced by) contemporary political and economic discourses, but also the style and form of presentation is influenced by contemporary artistic forms. Of course, modernists would argue that it was necessary for Darwin to employ such artistic forms, whether consciously or unconsciously, in order to communicate his theories to the public with the desired effect. If he had expressed his theories using forms that were distanced from contemporary discourses, it is likely that his work may have been marginalised.

Roland Barthes’ contention that continuous reinterpretation of metalanguages ends in the ‘[destruction of] the authority of all metalanguages’ (as quoted from A Reader’s Guide to Contemporary Literary Theory) further complicates the issue of the validity of Darwin’s ‘knowledge’. The theory that bourgeois ideology advocates the second nature of reading and the transparency of language may help to resolve this question: Darwin, writing in a scientific style, a key aspect of Enlightenment thinking (which also spawned the educated bourgeoisie), and attempting to be as widely understood as possible, was right to use this style. The postmodernist argument that the use of ‘old order’ forms and discourses invalidates Darwinian ‘knowledge’ and ‘truth’ in the present day, is difficult to reconcile because a form that conforms to one discourse (modernism) is being assessed according to the parameters of another, non-contemporary discourse (postmodernism), without being anachronistic.

The Communist Manifesto, written by Karl Marx and Friedrich Engels, is a very different kind of grand narrative to the Bible and The Origin of Species. While Darwin’s text deals with science, and Genesis deals with history and religion, Marx and Engels were writing on a subject at a time when their work was wholly based on theory, with no hard evidence rely on. The first Communist revolution did not occur until nearly 70 years after The Communist Manifesto was initially published, so much of the content of the text relating to the course of the Communist movement is speculative. The Communist Manifesto is also seen more of a solely political document than as a literary work, unlike the other grand narrative texts. However, there are elements of metaphor and allegory within the text, if only to assist the projection of the future for Communism. There are also definite links between the concepts upheld in The Communist Manifesto and beliefs in the bible. For example, the role of the Communist can be seen as similar to that of Jesus; both of whom strive for good, but are suppressed (or crucified) by the dominant bourgeois class who have everything to lose from allowing either of the heroes to continue advocating these new and dangerous belief that would involve emancipation and utopia for all oppressed and redemption for all mankind respectively. However, the major difference between the two texts is that the writers of the Bible and their contemporaries saw the Universe as a stable whole, and a mystery that should be explored, while Marx and his successors in the postmodernist age see the world as unstable and the potential for and rate of change phenomenal.

Interestingly, even though The Communist Manifesto is overtly intent on the overthrow of the bourgeois class, Karl Marx freely admits his admiration for the achievements of the bourgeoisie in their ascendancy to power, and the moulding of economy and society in their own image, bringing the world out of the Feudalistic economic dark ages. The postmodernist critic may see this admission by Marx as a refusal of omniscience, and a suggestion of postmodernist aesthetic to Marx’s writing. However, the elaborate (almost dramatic) literary style of Marx is such that he compliments his enemy before he begins his incisive criticism. The problem with this style of criticism is that in acknowledging the positive elements the bourgeoisie, Marx has given a justification for their existence as well as that of the Communist movement. While the adoption of this stance gives a more postmodernist, pluralistic view (perhaps in reaction to bourgeois modernism), this ambiguity has the potential to undermine Marx’s argument.

Marxism, exemplified by the content of The Communist Manifesto, is a departure from more straightforward postmodernist criticism compared to The Origin of Species and the Bible. However, it is important to remember, when assessing the validity of ‘truth’ and ‘knowledge’ in Marxism, that Communism has all but disappeared from the global political map. The Soviet Union has been swept away, and the regime in China is merely Communist in name, while Cuba has suffered because of the breakdown of the Socialist Bloc. It would seem that practical manifestations of Marxist theories were unable compete with Western capitalist ideals, Marxist political discourse still lives on. While the condition of postmodernism is perennially unstable, and meaning is in a state o continuous fluctuation, Marxism offers a reasonably radical but more stable discourse for those who believe that postmodernism is too deconstructive and unstable. However, the ‘truth’ of some Marxist contentions such as the rising up of the proletariat to seize power, may have been undermined by the fact that postmodernism has had such a profound effect on the class system that the groups that would be described as the proletariat have been dispersed somewhat by the evolution of the system. As for truth in the Bible, first modernism, and then postmodernism, has had the effect of totally undermining the ‘truth’ as a concept. Only very few fundamentalists believe in the totality of Biblical truth, with the majority of Christians to a varying degree seeing the Bible as a symbolic guide. However, the Bible is still a source of knowledge, in terms of the fact that there was a man who became a religious leader in Israel, and was crucified by the Romans, and also a continuing source of moral guidance to individuals and society, even though postmodernism has eroded these values to a certain extent.

The effect of postmodernism on Darwinism is to undermine the theory of Natural Selection, and the concept of ‘truth’ in that theory is difficult to uphold as a result. However, the ‘truth’ in the evolution of Man may still be a tenable concept the, in a high-tech post-modern age where society is continuing to find out more about itself and its physical origins.