Relativism is the view that the meaning and value of human beliefs and behaviors have no absolute reference. Relativists claim that humans understand and evaluate beliefs and behaviors only in terms of, for example, their historical and cultural context. Philosophers identify many different kinds of relativism depending upon which classes of beliefs allegedly depend upon what.
George Lakoff defines relativism in his book "Metaphors We Live By", as the rejection of both subjectivism and objectivism in order to focus on the relationship between them, i.e. the metaphor by which we relate our current experience to our previous experience.
The concept of relativism has importance both for philosophers and for anthropologists, although in different ways. Philosophers explore how beliefs might or might not in fact depend for their truth upon such items as language, conceptual scheme, culture, and so forth; with ethical relativism furnishing just one example. Anthropologists, on the other hand, occupy themselves with describing actual human behavior. For them, relativism refers to a methodological stance whereby the researcher suspends (or brackets) his or her own cultural biases while attempting to understand beliefs and behaviors in their local contexts. This has become known as methodological relativism.
Elements of relativism emerged at least as early as the Sophists.
One argument for relativism is that our own cognitive bias prevents us from observing something objectively with our own senses, and notational bias will apply to whatever allegedly can be measured without using our senses. In addition, we have a culture bias shared with other trusted observers, which cannot be eliminated. A counterargument to this is that subjective certainty and concrete objects and causes are part of our everyday life, and that there is no great value in discarding such useful ideas as isomorphism, objectivity and a final truth.
Another important advocate of relativism, Bernard Crick, a British political scientist, wrote the book In Defence of Politics (first published in 1962), suggesting the inevitability of moral conflict between people. Crick stated that only ethics could resolve such conflict, and when that occurred in public it resulted in politics. Accordingly, Crick saw the process of dispute resolution, harms reduction, mediation or peacemaking as central to all of moral philosophy. He became an important influence on the feminists and later on the Greens.
A common argument against relativism uses an inherently contradictory (self-stultifying ) notion: The statement "all is relative", which is either a relative statement or an absolute one. If it is relative, then this statement does not rule out absolutes. If the statement is absolute, on the other hand, then it provides an example of an absolute statement, proving that not all truths are relative.
The latter argument forms one of the first in reply to relativism, and needs more explanation.
You can reply to that by saying that only one thing in the world is absolute: relativism. Thereby solving this dilemma. This is a softer take on relativism. It says that the argument presented above is correct in a way. Not all statements are relative, but the only statement that is not relative is a statement "The only thing that is absolute is that all things are relative." This preserves relativism for all intents and purposes as it is applied to the real world, although in a weaker sense.
Followers of Ayn Rand claim the term "Objectivism" to describe her philosophy that adheres to the trichotomy of intrinsic/subjective/objective in metaphysics, epistemology, and ethics, which advocates maximizing individual capital rather than sacrificing to others - on the grounds that all good comes from trusting the productive, creative and free person. Rand was a vehement opponent of relativism, which she held to be highly destructive. Although they would likely differ with Lakoff's characterization of "objectivism" as a "straw man", it is clear that Lakoff intended at least some criticism of capitalism in his early work, and some support of moral relativism (which Rand despised). To a lesser degree his criticisms apply also to Karl Popper, Kant or Aristotle.