There is a long philosophical tradition that has claimed that universality and abstractness have no legitimate basis in our experience of reality. This is usually called the "problem of universals" and it derives from the fact that we humans experience objects in the real world as discrete, concrete and individual. Yet, this is contrasted to our thoughts, which experience and know about objects in more general and abstract, or universal ways.
As an illustration, cars and houses--and many objects in the world-- may be "green", and we can understand that "green" is a more general property of things, or rather, a universal. "Green" is also an abstract concept which can be thought of without connection to a particular object, but it does not actually exist separately from a particular object. The philosophical conundrum that puzzled philosophers is trying to understand how such universal and abstract aspects of real things exist, when our experience in the real world is only of specific, individual objects?
Two prominent philosophers who considered this problem and concluded that universals/generalities and abstractness were not legitimately derived from empirical experience were Hume and Kant. Over the next several hundred years, their positions were further refined and expanded on in this area.
Hah! I know what you are thinking--who cares about such an esoteric concept?
Well, let me tell you that this particular philosophical problem is not abstract at all, but one which pops up all the time in current discussions--even on this blog. How you deal with the concept of universals turns out to be extremely important, particularly in rational discourse, where objective reality and truth are necessary.
Consider this: if there is no way to account for generalizations or universals through empirical experience, then all such attributions may be considered subjective and hence, invalid.
How many times on this blog have you heard the trolls scream repeatedly about how I lump all people of a certain political belief into the category of "the left"; or how I generalize the behavior of a "small" group of deranged Muslims as "Islamic". No, no, no! they all cry--this is unfair; this is totally subjective on your part, Dr. Sanity; this is completely invalid!
Though a generalization, I think the above fairly sums up their attitude. The Kantians reading this will have to forgive me for making such a universal and rather abstract conclusion, I guess. But, my essential point is that not only is this the way I happen to think, it is the nature of human consciousness itself to perform this function. By trashing this aspect of human consciousness, the result is no more and no less than severing the human brain from reality.
Let me go one step further in my universalizing tendency. The underlying assumption of these trolls--another generalized concept, I admit, though I am sure that trolls that they are, they couldn't be bothered to consider it abstractly--happens to be one of the basic and crucial foundations of Postmodern thought (discussed here , here and here if you don't know what Postmodern philosophy is all about) : by making universals and generalizations completely subjective , they have successfully invalidated anyone's attempts to understand reality and truth.
As an example of the very different philosophical and moral universe the Postmodernists occupy; as well as the havoc they are wreaking in both the ability to engage in rational discourse and effectively deal with the real world, let's consider something written by Victor Davis Hanson a while back:
Maybe the rise of specialization in the university causes us to stress the exception rather than the rule. Or perhaps the rise of personal anecdote in lieu of analysis, common in our therapeutic society, explains why we shy away from generalization.
It is certainly true that the emergence of minority rights and grievances has chastised Americans from making generalizations that are valid in the majority of cases, but ridiculed because there are occasional exceptions. If one were to conclude that Swedes were dour, prone to drink, large, and sometimes moody, based on what I have seen of my family, I would tend to agree as a rule—with the qualifier I have met many who were sunny, tiny, and abstainers. But nevertheless that stereotyped portrait remains a good enough truism.
I raise this with exasperation since lately we are told that various radical Islamic groups—Hezbollah, Hamas, Al Qaeda, or the Muslim Brotherhood—are not all alike. But who is? And what does it matter if their generic hatred of the West and the United States in particular is predicated on the West Bank, Lebanon, Afghanistan, or our failure, according to Dr. Zawhiri, to sign the Kyoto accords? I’m sure our grandfathers did not resent the insensitive lumping together of Mussolini with Hitler and Tojo because there were undeniable differences between Bushido, National Socialism, and Fascism.
Indeed, this fear to generalize has gotten so bad that we cannot speak of “Arabs” as generic people, even though they themselves, in perfect Pan-Arabic fashion, do so, and, of course, speak of Americans as a predictable cadre. I have visited Egypt, Iraq, Kuwait Libya, Palestine, and Tunisia and most there I met seem to entertain real antipathy for Israel, express a strange simultaneous attraction for, and anger with, the United States, share certain ideas about the role of women, religious tolerance, Islam, Western culture, and the role of family patriarchs. And while there are obviously many who resent such a characterization, it is all the same a valid generalization.
Indeed, as Hanson suggests, it is extremely exasperating to live in a world that is held to be "all trees and no forest."
How is it surprising that rhetoric in today's world has decended into vicious ad hominem attacks--such attacks are inevitable when you can only talk about individual trees and not the forest in which they dwell. Why do you suppose that effective policies can never seem to be formulated or implemented to deal with pressing problems (no matter who is in charge) --when problems can only be conceptualized as inescapably subjective, and therefore limited in scope?
Let me end by quoting the invaluable Stephen Hicks:
Suppose a thinker argued the following: "I am an advocate of freedom for women. Options and the power to choose among them are crucial toour human dignity. And I am wholeheartedly an advocate of women's human dignity. But we must understand that a scope of womans's choice is confined to the kitchen. Beyond the kitchen's door she must not attempt to exercise choice. Within the kitchen, however, she has a whole feast of choices--whether to cook or clean, whether to cook rice or potatoes, whether to decorate in blue or yellow. She is sovereign and autonomous. And the mark of a good woman is a well-organized and tidy kitchen." No one would mistake such a thinker for an advocate of woman's freedom. Anyone would point out that there is a whole world beyond the kitchen and that freedom is essentially about exercising choice about defining and creating one's place in the world as a whole....The point for any advocate of reason is that there is a whole world outside our skulls and reason is essentially about knowing it.
Thus by insisting that the mind is only capable of evaluating the "trees"; by invalidating any attempts to see the "forest", Postmodernism has successfully isolated our minds from objective reality and truth.
And, if that is too much of a generalization for you, too bad.