During the last century the landscape of theoretical sciences has to some extent been dominated by thinking on the very small (the world of atoms) and on the very large (the world of galaxies); of course, one must not forget the inspiring connections between the two universes (there have been “explanations” of phenomena that earlier were just mysterious). With numerous and notable exceptions it is as if, during this period, it has not been fully appreciated that stimulating challenges can be found also in the ordinary-scale activities of daily life. By “activities” I have in mind research in fields like medicine, ecology, and technology: theoretical problems that appear in those contexts have often been either ignored or handled with rather primitive methods. One expression of the situation is what I personally like to refer to as the Cassandra syndrome: when for instance a formal matter – like an elementary inconsistency – is pointed out to a scientist the response has frequently been in the shape of replies like “naturally”, “self “evident” or “of course”, after which the matter is totally ignored. The reason for this only the gods of the Olympus can tell (cf. the last paragraph below).

But even if we can’t give the reason for this syndrome there is today no question of us facing an attitude, a direct practical consequence of which is that, in areas like medicine and ecology, the theoretical instruments are habitually not up to the standard of the experimental instruments; or more directly, too often the potential of the experimenter’s skill is not fully utilized.

Let me here emphasize the term “theoretical instrument”. That is, the view I apply is:

 

     Theory is a necessary instrument for design and interpretation of experiment.

 

In other words, I apply a very corporal look at the term theory: it is an instrument for the experimenter at design and interpretation of experiment, and that’s all. Phrased differently, theory is the language in terms of which the investigator can contemplate the nature around him and communicate the results. One might say that I wish to get rid of the thought of deepness behind words and phrases like “explanation”, “law of nature” and things like that. To be more specific, for me a notion like law of nature is nothing but a relation that one has found often being practically useful, and it is a result of a particular choice of language (theory) together with a certain set of experiences. When one for instance says that the same laws of nature should hold for different observers (like in the theory of relativity) it simply means that same empirical rules should apply. Yes it is a matter of empirical experiences together with a particular choice of concepts (language). For instance, some time ago I made a colleague upset because to him the famous Schrödinger equation is a “law of nature” (something deep) whereas I called it a postulate: yes it is an ingenious postulate, but so what.

And this brings me directly to the term theoretical sciences, which to me means the job of constructing theoretical instruments for design of experiments and interpretation (“understanding”) of experimental results. So let us for a moment consider the “evolution of theoretical sciences”, and apply a kind of historic point of view. It then seems correct to say that the development of individual theory (instrument) has frequently been characterized by abstract and formal beginning, followed by period of substantiation, during which the theory’s formulation becomes less and less abstract. One might say that over the years it moves from post-PhD seminars to high school. And often this kind of development has taken generations to accomplish.

And it is here that the “Cassandra syndrome” often shows itself: a problem is considered so elementary that it is not worthy of recognition.  Thus, too common is the situation where the researcher’s interest is totally concentrated on a specific model so that he does not see the fact that the model is formulated in a language of unclear physical significance. For instance, when dealing with chemistry of macromolecules it has for decades been accepted that that one has to deal with molecules of uncertain weight (the classic “molecule weight” is replaced by “weight distribution”) at the same time, however, that the models of reaction are formulated in symbols that are totally meaningless should not the involved molecules have definite weight. All too frequently the problem has been solved with uncontrollable use of the notion of “approximation” (in two cases I have met the wonderful term “representative molecule”) which means a sloppiness that hardly fits in a scientific context. To me the neglect of the elementary occurs often – too often. Here I then use the term elementary somewhat as a synonym to basic;  and above all, that something is elementary does by no means  imply that it necessarily is simple.