The distinction between theoretical and observational physics might confuse people as to the difference between theory and practice. At first, it might look like the empirical aspect of physics falls on the side of practice. Einstein was a theoretical physicist. His most famous conjecture is the theory of relativity, and we say that this theory has been validated by empirical observation. Similarly, we call Darwin’s celebrated discovery the theory of evolution. As a theory, it is falsifiable in the sense that observation can either prove or disprove it. Both Darwin and Einstein theorized that x is the case, but their constructions remained conjectures (however forceful or convincing) until they were either proven true or false by empirical evidence. Hence theory and observation seem to be opposed to one another. As we saw last time, however, both are theoretical kinds of behavior falling under a more encompassing sense of the word “theory” that includes both contemplation in the sense of speculation and contemplation in the sense of observation. Indeed, the word “speculation” already contains a reference to observation. The Latin speculari means to watch, examine, observe. On the other hand, even after it has been validated, we continue to refer to Einstein’s discovery as a theory and, as unlikely as it seems, Darwin’s theory of evolution might theoretically still prove false if new evidence arises invalidating it. The point is that the distinction between theory and empirical observation is one that falls within theoria itself, which can only then be meaningfully opposed to praxis.
What distinguishes theory from practice is not empirical evidence but the way the subject comports toward the object. In both theory and practice the subject is concerned about the object, but this concern manifests itself differently as either a practical or as a theoretical kind of concern. For instance, a farmer relates to a cow by feeding and milking it. When milking the cow, the farmer is not theorizing about or even thematically objectifying the animal. The farmer might not even be thinking about the cow at all but about a fence that needs mending. In contrast, the scientist qua researcher relates to the animal by observing it, by keeping it explicitly in his or her sights while also keeping a studied distance. While the farmer might learn a lot about the cow in the process of tending to it, the end the farmer has in mind is sustenance, an existential end. In contrast, the end the researcher has in mind is knowledge (ideally, knowledge for knowledge’s sake even if this knowledge can later be used for a practical purpose). I can relate to a tree by using it as a sort of tool, by taking shade under its branches, in which case my relation to it is not theoretical but practical. Or I can objectify the tree by approaching it as a botanist, that is, I can begin observing and speculating about it. Again I can use light to read a book, or I can turn the light itself into a thematic object. I can use an implement to drink out of, or I can examine it to see what it is made of.
While the line between theory and practice is not always clear, in general we may say that science takes a theoretical stance toward the world while our normal way of relating to it is practical. Theorizing entails a certain degree of abstention from praxis in relation to the thematic object. I emphasize “in relation to the object” because theoretical behavior often mixes with practical behavior, as when equipment is set up or used in a lab. Because the lab equipment is not the object being examined, the researcher’s comportment toward it is practical. However, the piece of equipment can still turn into an object of theoretical inquiry with a simple change in the way the researcher relates to it. This might happen if the piece of equipment breaks down and the researcher tries to determine what’s wrong. She then begins observing and speculating about it. If this tendency gets developed far enough, it becomes science.