There's often something else in the background. A weird platelet count, a low sodium level, a little anion gap--something that might be easier to ignore than to try to figure out how it fits into the clinical picture. I'm assuming that I'm going to at least notice these annoying details. That is, I'm already assuming that I'm vigilant.
Vigilance makes a doctor good. A good doctor will diagnose the pneumonia and treat it. Curiosity makes a good doctor better. A curious doctor will be driven to figure out why these other lab values are a little off because, it’s true that there could be all sorts of silly explanations for an out-of-range test result, yet the doctor's job is not only to figure out what's not wrong, but also--when the dust settles--what is.
Like any other job, medicine can become routine. The evidence that we have been accumulating on medical and surgical interventions has to some extent standardized our practice. Data have helped to define the 'standards of care' for investigation and management of many diseases. Some of these well-studied diseases for which there is more or less widespread agreement on management include heart attack, heart failure, diabetes, many infections, and certain kinds of trauma, to name a few. The purpose of evidence-based medicine however is not to make the job of the doctor easier nor is it to make sure everyone gets the same treatment just for equality's sake, but rather to apply particular medical decisions that have been shown, hopefully in high-quality experiments, to be effective. The medical community decides that interventions that improve outcomes should become standard because they're better.
The word that doctors use is not 'standard,' though. It's 'guideline.' This is not because doctors think that they're better than everyone else and that rules shouldn't apply to them. Rather it's to make room for judgment because it is impossible to study every intervention in every population of potential patients, and because even effective interventions are rarely effective for every eligible patient. We have therapies that may approach 100% efficacy (eg, penicillin for syphilis), but they are few and even they're not perfect. We think that preventing death in only 1 out of 42 people treated with a beta-blocker for two years after having a heart attack is pretty good. In addition, accepted algorithms for investigating disease will not include every possibility, so the doctor needs to have an index of suspicion for diagnoses that may not be on any algorithm.
So, is this science or art?
Everyone knows that doctors like to say that medicine is as much art as science. My own quibble with this has nothing to do with medicine (nor with art or science for that matter) but rather with the public's perception of these things. The word 'science' evokes--in most people I think--accurate, precise, and reproducible results. But science is nothing more than approximations and arbitrary constants, especially in the practical application of physics, chemistry, and biology. Engineers have to compromise and allow for some inaccuracy and imprecision in their end design ('tolerances') because they have to live in the real world where mathematics has to be a little looser than it is in the classroom.
At its heart, science is built on hypothesis-testing. Who comes up with hypotheses? People. Observant, curious, creative, artistic people. If hypotheses could be generated based on precise formulae then we could just build a science machine and let it figure out the secret to life, the universe, and everything for us. We know how that would turn out.
Science, like art, requires creativity (neither science nor art are sui generis things). I'm not going to pretend that I can define art, but maybe besides creativity it might include some element of perception by an observant person. At its simplest, then, art is a creative person's response to an observation synthesized into some form (canvas, performance, sculpture, music, prose, poetry, speech, hypothesis--whatever). Science is the same thing I think. Isaac Newton observes that an apple falls from a tree. It's fair to say that millions of people have seen this happen before him but he is curious--inspired--enough to design unique and creative experiments to calculate the rate at which it falls. He is finally able to synthesize his data and determine the gravitational constant (which is an estimate). Newton's laws are works of art. Da Vinci's sketches are science.
The doctor is a scientist, but the scientist is an artist and the artist is a curious human. The uncurious doctor is a mediocre one because he is just a human who is happy with what he knows and doesn’t care about what he doesn’t.
