"The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful." -- Henri Poincaré
I relate very strongly with Poincaré's words. The quote expresses an attitude that moves me in my day-to-day life. Beauty, however, is a fuzzy concept. "Beauty lies in the eye of the beholder", as people say (or Plato, more exactly). These are my personal views on the beauty of social systems.
It is in the lack of common denominators where I see beauty. The range of scales and the diversity that social systems display is, to my mind, unparalleled. Yes, biological systems are very diverse. However, biological systems are greatly limited by material, spatial, and energetic constraints. Moreover, biological systems have in place many mechanisms that limit the diversity and imposes homogeneity. For example, individuals within a same species are to most purposes the same. Same heights, same anatomy, same behavior. In other words, it is easy in biology to find common denominators. It is precisely the presence of common denominators which allows biologists to categorize individuals into species, genus, orders, kingdoms, etc. The same applies to other disciplines (think of physics with their fundamental particles and fundamental forces). Common denominators are, in contrast, the exception in social systems.
Let me expand. Although social systems are composed of mainly one single species (humans), and may seem very homogeneous, this species' capacity to control matter, space and energy, and its capacity to transfer information from brain to brain so efficiently, has made social systems to explode in heterogeneity. For sure, physical constraints still exist. But since our main currency is not matter or energy, but information, the bounds that constrain us are weak (or non existent). So, for example, we now live much longer than before, the size of our social groups are now enourmous (think of today's megacities with populations of around 40 million), and cultural diversity has grown exponentially. There are no limits to how much money a person can have, or how much knowledge a person can access. And people now specialize in a diversity of occupations and activities whose coordinated efforts have allowed our species' influence to reach other planets. You can see, much of what has happened to the human species is precisely because we have the capacity, at the individual level, to be less like others (this, of course, has also brought many problems like inequality and discrimination, but these are topics for other posts).
Now, let me be very clear. Lack of common denominators does not imply lack of regularities. And by transitivity, a lack of common denominators does not in any sense preclude us from doing Science. Lack of common denominators, in fact, is itself a regularity. And it's a beautiful regularity. A regularity that begs an explanation.
To mistakingly confuse a lack of common denominators with a lack of regularities prevented biologists for many years from identifying biological laws. By biological laws I mean regularities that can be expressed in mathematical terms. This confusion, instead, led them to believe that biology's only job was to document and describe the particulars. The situation is worse in economics. While biologists have explicitly recognized the inherent diversity of biological systems, the lack of common denominators in social systems, in my opinion, has been largely neglected by economists.
Economics, surprisingly, has gone through exhausting efforts to describe economic systems as composed of representative agents, firms, cities, countries, goods. This, in my mind, means taking away all the beauty and fun of social systems. But it also means moving away from reality.
This special feature of social systems poses great scientific challenges. But, again, this only makes studying them even more exciting.