Historical periods have unique and often hidden assumptions that shape the structure of knowledge, making past ways of thinking fundamentally distinct from our own today.
Book: The Order of Things
“Historians want to write histories of biology in the eighteenth century; but they do not realize that biology did not exist then, and that the pattern of knowledge that has been familiar to us for a hundred and fifty years is not valid for a previous period.”
Why didn't biology exist before?
French philosopher Michel Foucault suggests that each historical era has its hidden assumptions that define what counts as knowledge. He called these invisible assumptions "epistemes".
For example, in the eighteenth century, the concept of biology as a systematic study of life did not exist. Instead, people studied "natural history". They categorize animals and plants, but never investigate the underlying biological processes. And surprisingly, this approach to understanding life was more closely connected to their economic ideas than to anything resembling modern biology.
Another example is how language changed over time. Previously, language was considered merely a representation of ideas. After Immanuel Kant, language evolved into its own distinct field of study. Mallarmé famously answered Nietzsche's question "Who is speaking?" with "Language itself." Literature is neither resemblance nor representation, but becomes a force of its own, with branches like analytical philosophy, with our Weekly I/O's best friend, Wittgenstein.
These changes demonstrate that knowledge is never timeless or universal. Rather, each era shapes its understanding through hidden rules it unconsciously accepts.
What we see as obvious truths today might be strange or even laughable to future generations. The other direction might also be true: every breakthrough is at first laughable and ridiculous.