An empiricist tends to place an emphasis on observable evidence, a rationalist goes off of reason, but why couldn't you mix and match them. If you Google them, you see a lot of philosophy pages with things like "Ratioanlism vs. empiricism" and so on. http://plato.stanford.edu/entries/rationalism-empiricism/ Some psychology tests place you as being more ratioanlist or empiricist, I believe INTPs and INTJs are more rationalist. But why can't you mix and match? For example, I believe it's extremely important to observe things and then to test them, and then reason from them. The reason helps because there may be tests you could do that are misleading or do not show the whole picture, and thus the test needs to be refined (dropping two items of different weight from a low height and a high height, for example). And, of course, testing might show that your the principles you had originally reasoned on were clearly wrong, as you tried the conditions. Wouldn't most people really be a mix of the two, rather than an either/or scenario?