In contemporary times, there are two main ways to attain knowledge: by contemplating or thinking, and by experimenting or experiencing directly whatever you wish to know about. The first way is called rationalism, and the second is empiricism. These ways together form what is known as epistemology, or the philosophy of knowledge.
Rationalism is different from empiricism in how one attains knowledge. Rationalists attain knowledge through logical inquiry and contemplation, while empiricists get knowledge through experience and experimentation. Rationalism is a tool used mostly by the humanities, which include literature, art, philosophy, and so forth. This is because the humanities are not based on experimentation, but on contemplation, logic, and verbal fluency.
Empiricism, on the other hand, is nowadays the main way science develops, i.e, through experience and experiment-based research. For more on the relationships between Science and Logic, visit this article I wrote, called "The Two Heads of Wisdom"
The question is, is rationalism sufficient as a tool for gaining knowledge? Empiricists, on the other hand, provide a direct source of information by experiencing their source of knowledge, rather than thinking about it. Not only do empiricists need less cognitive effort to attain knowledge, they also experience the source of knowledge directly, unlike rationalists, who do so indirectly. Rationalists may get various insights, some of which may be incorrect or partially incorrect, due to lack of direct experience with the subject they venture forth in intellectually.
I defend rationalism because there are some aspects of existence which cannot be experimented with, not because it is immoral, but because it is impossible. Abstract concepts and ideas cannot be tested nor measured, and thus the only way to understand them is through logical inquiry.
The most cliché example of this is the meaning of life. You cannot experiment with meaning, as meaning is purely abstract, and cannot be tested nor experienced in a specific time and place.
You cannot sense meaning in any way, and there is no way to measure a hierarchy of “meaningfulness” in things and beings. This issue can only be used as a source of knowledge indirectly, in the form of rationalism, to extract not correct but possibly-correct insights, with the most logical explanation being the most possible truth.
Personally, I view myself as more of a rationalist than an empiricist, both when writing articles and when it comes to my personal life. As of the publication of this article, I have never been in a romantic or sexual relationship, and yet I have written a lot about it without the necessity to experiment with it myself. (It is also one of the reasons I chose to abstain from it at least for now.) I have never jumped off a cliff, yet I know that doing so would either injure me terribly or kill me. Many more examples could be written if I were to dedicate enough time and thought, but it seems that I have made my point that empiricism is not always necessary in order to reach some truths and insights.
In summary, when it comes to the attainment of knowledge, we should be able to distinguish truths that can only be achieved with experimentation, and truths that can be reached simply by extensive thinking and maintaining/improving the logical structure of said thought process. This is why some people are more logical than others—logic is to be taught, not born with, in order for us to become more logically-cohesive beings.
There is also one thing that we, as rational beings, should be careful about: fake news, the delivery of false information. This can badly hurt the rationalist process of pursuing knowledge. When it comes to reading or watching videos about a specific subject, the more the merrier, because if you depend on only one source of information, you might find yourself more misinformed than you might think you are.
Arguably, the same can also be true in the empiricist way of pursuing knowledge, as there could be times where it is insufficient to only do or learn about one experiment. What if another research could lead you to a different result? Hence why I believe scientists should do multiple experiments in order to reassure the outcome of their experiments.