In European thought, at the end of the 19th century, we find two groups of thinkers who oppose each other systematically across a number of topics.
On one team, we find a series of "determinists"; deterministic thinkers propose, for our purposes, the notion that what you are, and what you do, was previously decided, not by you. Determinism, then, denies that human beings make any significant choices. Marx represents economic, political, and historical determinism: he says that the future has already been decided, and it is inevitable that a certain series of economic and political events will occur, and that the world will arrive at a specific economic and political condition. Darwin represents biological determinism; the human race, and each particular human being, is as it is because of genetic and environmental factors. Freud represents psychological determinism: the choices I seem to make are actually determined by events earlier in my life - my parents and early childhood experience will dictate whether I choose Coke or Pepsi, Democrats or Republicans, Protestantism or Roman Catholocism. By denying that human beings make significant choice, determinists deny any "meaning" to human life, at least as most people would understand "meaning" - thus, they are ultimately nihilists. This team of determinists is also a team of materialists: by this we mean that they deny the existence of anything besides physical objects. So they would say that there are no such things as ideas, memories, spirits, minds, souls, emotions, etc. Marx's materialism causes him to conclude, for example, that we should get rid of marriages and families, and that men should be allowed to view all women as their sexual property; since Marx's economic theories revolve around the ideas that all men should hold all objects as common property (and that therefore there is then no property), so his materialism, which views human beings simply as physical objects, causes him to say that all men should hold all women as common sexual objects (and that therefore there is then no such thing as marriage or family): this amounts to the assertion that, according to Marx's ideas, women are property. Also on this team would be Friedrich Nietzsche, whose message to the human race is that it is merely an instrument of higher forces and drives in the universe: human beings should not credit themselves with meaning, value, or dignity.
On the opposite team, we find people like Dickens, whose novel, "A Tale of Two Cities", revolves around a series of individual human beings who make important and meaningful choices, and those choices have significant impact on other human beings and on the world. Dickens is telling us that human beings are not determined like chemistry and physics, but rather have a freedom to decide; he is telling us that our choices have consequences, which can be good or bad. Ibsen shows us a family which is falling apart, in which the wife and the husband fail to show each other the support and warmth which is a real marriage; Ibsen is showing us why we should reject Marx's idea that women are property: Ibsen says that a loving and mutually affirming marriage is possible only when the wife and husband understand that they can make a meaninful choice to be faithful and supportive to each other. Kierkegaard, as the founder of existentialism, directs his attention to the individual: meaningful choices, he says, are made by the individual, not by groups or categories of people; thus I must make my decisions as a single human being, not as a member of my nation or profession or ethnic group or political group. Dostoyevsky shows us that, when faced with painful circumstances (whether the pain be political, emotional, or physical), the human being can triumph by making an "inner revolution", not an outer revolution; Dostoyevsky is saw help for each human not in a political movement, but in an internal change.