In the beginning, there was the list.
Some of our oldest written texts are, in fact, just lists of things: types of trees, types of bird, that sort of thing. They may have been used for teaching vocabulary in writing, but they also serve as a foundational element for knowledge, one so basic that the average person today barely even thinks about it. But how can you learn about Stuff if you haven't first thought about what Stuff is out there?
The Onomasticon of Amenope goes a step further. Not only does this Egyptian text from three thousand years ago set out to help the student learn "all things that exist," but it organizes them into loose categories, summarized by Alan Gardiner as things like "persons, courts, offices, occupations," "classes, tribes, and types of human being," and "the towns of Egypt." This is a vital step in scholarship, not only in the past but the present: even today, we wrestle with questions of categorization and how best to group things, because there's no single "right" answer. What system is best depends on what you want to use it for, and how you approach this issue reveals a lot about where your priorities are. (Think of a grocery store: what's revealed by having dedicated shelving for things like "Hispanic foods" and "Asian foods," and what items could arguably be placed among them but aren't.)
Another very early category of scholarship is travel writing or travelers' reports -- basically, accounts of ethnography and natural history covering foreign lands. These have often been highly fanciful, reporting things like people with no heads and their faces in their stomachs, but why? It's hard to say for sure. In some cases the information probably got garbled in the transmission (think of the game "telephone"); in others, the observer may have misunderstood what they were seeing; sometimes the teller deliberately jazzed up their material, and sometimes they made it up out of whole cloth, perhaps to support whatever larger point they wanted to make. From our modern perspective, it often looks highly unreliable . . . but it's still a key element in laying the foundations of knowledge.
Once you have foundations, you can start building upon them. Much ancient scholarship takes the form of commentaries, works that aim to explain, expand upon, or contradict existing texts, often by pointing at another text that says something different. You also get textual criticism, which is our modern term for a practice going back at least two thousand years: when works are copied by hand, there is significant need for scholars comparing the resulting variants and attempting to identify which ones are the oldest or most accurate. Basically, undoing that game of telephone, lest things get garbled beyond comprehension.
What you
don't tend to get -- not until more recently -- is research as we think of it now. There absolutely were people who attempted to explain how the world worked, but they largely did so by sitting and thinking, rather than by actively observing phenomena and testing their theories. That doesn't mean they weren't curious about things, though! How the heck does vision work, or smell? Why do objects fall down? What makes the planets seem to "move backward" through the sky, rather than following a straight path? What engenders disease in the body? People have been trying to answer these questions for thousands of years. The pop culture image of pre-Enlightenment science is that people just said "it's all because of the gods" and stopped there, but in truth, pre-modern people were
very interested in finding more specific answers. Yes, it was all due to the gods, but that didn't mean there weren't patterns and rules to the divine design. Even medieval Christians, often assumed to be uninterested in or afraid of asking questions (lest the Church come down on their heads), argued that better understanding the mechanics of God's creation was an expression of piety, rather than incompatible with it.
But it's true that they largely didn't conduct experimentation in the modern, scientific method sense. Science and philosophy were strongly linked; rather than aiming to dispassionately observe facts, much less formulate a hypothesis and then see whether the data bore it out, people sought explanations that would be in harmony with their beliefs about the nature of existence. Pre-Copernican astronomy was shaped by philosophical convictions like "the earth we humans live on is supremely important" and "circles are the most perfect shape, therefore the one ordained for the movement of heavenly bodies" -- because why would divine entities arrange things any other way?
Scholarship and science were also strongly shaped by respect for past authority, to the point where luminaries like Aristotle were practically deified. (Or
literally deified, in the case of the Egyptian chancellor Imhotep.) It marked a tremendous sea change when the English Royal Society in the seventeenth century adopted as its motto
Nullius in verba, loosely translated as "take nobody's word for it." They resolved not to accept the wisdom of yore, not until it had been actively tested for veracity . . . and if it failed to hold water? Then out it went, regardless of who said it and how long it had been accepted as dogma.
This is, of course, a
highly simplified view of the history of science. Not everything proceeded at the same pace; astronomy, for example, has an incredibly long history of precise observation and refinement of instrumentation, because correctly understanding the sky was vital to things like the creation of calendars, which in turn affected everything from agriculture to taxation. Biology, meanwhile, spent a lot longer relying on anecdata. But it's vital to remember that things which seem completely obvious to us are only so because somebody has already done the hard work of parsing the mysteries of things like the circulation of blood or the chemistry of combustion, which in fact were not obvious at all.
And this opens an interesting side door for science fiction and fantasy writers. The history of science is littered with theories eventually proved incorrect -- but what if they weren't wrong? Richard Garfinkle's novel
Celestial Matters operates in a cosmos where Aristotelian biology and Ptolemaic astronomy are the reality of things, and develops its story accordingly. There's a whole Wikipedia list of
superseded scientific theories, which could be fodder for story ideas! (But tread carefully, as some of those theories have pretty horrific implications, especially when they have to do with people's behavior.)
It's also worth thinking about what theories we hold today will look hilariously obsolete in the future. We like to think of ourselves as having attained the pinnacle of science and everything from here on out is just polishing the details, but you never know when an Einstein is going to come along and overturn the status quo with a new, deeper explanation of the facts. Of course none of us know what those future theories will be -- if we did, we'd be the Einsteins of our generation! But if you can spin a convincing-sounding foundation for your theory, you can present the reader with a world that contradicts what we think we know today.

(originally posted at Swan Tower:
https://is.gd/jG7X6K)