system
Given the following post, respond as if you're commenting on Reddit:
human
CMV: Engineers and MDs are not scientists (except those conducting empirical research).

I have seen several examples, in the past few years, of engineers and MDs (medical doctors) claiming to be scientists. Many of these situations have been with friends or acquaintances. I also sense very strongly that engineers and MDs "identify as scientists," by claiming the "science" side in online or televised discussions/debates, and similar behaviors that are not open declarations of the identity but seem consistent with it.

Some engineers and MDs conduct science; that is, they perform empirical research. Those individuals are scientists. However, the vast majority don't, so they aren't.

"Science" has two major meanings. The first is archaic, and it means something like "any structured, disciplined pursuit of knowledge." By that definition there are quite a number of "sciences," including philosophy, mathematics, the arts, public administration, etc. However, the more modern (i.e., past century or more) meaning of "science" is much more specific: the process of using (presumably validly) the scientific method to generate knowledge. 

By the more modern (and, by far, most common) definition, engineering and medicine are not sciences; they're technologies. Engineers and MDs, overall, do not discover or create generalizable knowledge by way of the scientific method; rather, they apply knowledge generated by others (i.e., by scientists).

The problems, I think, are 

1. "Science" and "scientist" have progressively become cooler or more desirable as labels. Everyone wants to be a "scientist" as scientific explanations increasingly dominate many domains of life. 

2. Engineering and medicine are more closely tied to the results of science than most fields. Design, business administration, etc. use science opportunistically but are not locked into it the way engineering and medicine are. Therefore, in important ways, engineering and medicine are more *scientific* than other fields, in that they must use the fruits of scientific research more conscientiously to obtain results.

3. This one is my own opinion, and I can't prove it, but I'm certainly not alone: engineers and MDs (especially MDs) have professional pride and entitlement trained into them, in many cases. They are encouraged, implicitly and (at least for MDs) explicitly to think of themselves as superior to people in other professions in specific ways. This view has a basis in reality, as engineers are probably far better at solving many problems than the average person, and MDs have great expertise in a critical area: the functioning of human bodies. However, spending time around MDs will leave most people with the sense that MDs expect/demand a level of professional/(personal) respect that goes beyond that specific dynamic. Although not as pronounced as the MD case, it is not hard to find hundreds or thousands of cases (see: reddit) of engineers suggesting that complex problems in social, political, linguistic, biological, psychological, philosophical, etc. domains (i.e., not in engineering) could be solved more easily if they were addressed by engineers.

To sum up, engineers and MDs share a close relationship to the fruits of scientific research and a sense of professional pride or even entitlement. This, coupled with the increased coolness of "science," has led many engineers and MDs to self-identify as scientists. However, with the exception of those conducting empirical research, they are not scientists.

Note: Not being a scientist doesn't mean a person (or their profession) is of lower worth, though Westerners have had a weird hierarchy, historically, of valuing the "thinking" professions over the "doing" professions (which, IMO, is crap). Being a scientist isn't a "better" thing than being a technologist -- science has few benefits without the armies of individuals innovatively applying it, and scientists are generally not trained for that. However, we have decided that "scientist" sounds really cool, so I think we have some biases, here. But that's all they are, biases.

*Edit*: It's noonish Eastern US time and I should do some real work. Because apparently I have a real job. So I'll get back to this later tonight, I think. Thanks to everyone who has commented; my views have, indeed, changed to some extent, and perhaps they will more, later on.
gpt
Engineering and medicine are applied sciences. To get a degree in either requires a huge amount of scientific study and understanding of the scientific method. 

I don't think it's true that engineers *only* apply knowledge generated by others and *never* conduct empirical research or use the scientific method. It's an integral tool in the arsenal of an engineer. Sure you try to use established knowledge when possible, because that's practical. But the complexity of large projects means that you will inevitably be asked a question that will require methodical research to answer.

*Why are we losing 5% efficiency off the expected performance of this widget? How can we work around this problem? Will this problem increase as the project progresses and we add more widgets around the widget? What is the risk of failure with this problem, what is the risk of failure with our solution?* 

You can't look the answers to these questions up in a reference book, and you can't professionally answer the questions without empirical research.