There are many examples of dreams influencing the course of human history. Mendeleev’s dream of the periodic table is the best-known case; Kekulé’s dream of the benzene ring and Niels Bohr’s dream of atomic structure belong to the same family of stories. In each case, the dream supplied not so much a finished answer as a structure — a way of seeing relationships that made a physical phenomenon intelligible.
The dreams René Descartes had on the night of 10 November 1619 seem different at first. There was no direct answer to a clearly formulated problem — indeed, there may not even have been a clearly formulated question. Yet Descartes himself regarded the experience as decisive. It became associated with his search for a scientia mirabilis, a “wonderful science” capable of revealing a deeper unity behind apparently separate fields of knowledge.
Descartes recorded the dreams in a notebook known as Olympica, which has not survived. Fortunately, they were later described by his biographer Adrien Baillet.
The philosopher Merab Mamardashvili, who devoted considerable attention to Descartes, offered a particularly interesting interpretation of this episode. What Descartes glimpsed, Mamardashvili argued, was not an encyclopedia containing all possible knowledge, but something more fundamental: an underlying harmony connecting things in such a way that, even without knowing the whole, one can begin from a single point and move correctly.
Mamardashvili describes it this way:
Descartes dreamed that there exists an inner, hidden harmony connecting all things in such a way that, without knowing them all, one can grasp one of them and proceed correctly. The world is structured according to laws of which I may be unaware, yet these laws make it possible for me, from a local point of darkness, to perform an act that would otherwise seem to require knowledge of the entire universe. I do not know all those laws, and nevertheless I can act. There is, therefore, some assistance provided by the world itself — what Descartes calls a catena, a chain, like Jacob’s ladder leading upward.
The important idea here is not simply that “everything is connected to everything.” That claim is too vague to be useful. The stronger idea is that the world has enough structure for us to navigate it locally without possessing a complete map.
Descartes sometimes expressed this image through the notion of catena mundi — the chain of the world, the connection of things. Whether or not we treat it as a fully developed doctrine, the image fits remarkably well with the intellectual project that later emerged in his philosophy: moving from what is known toward what is unknown through ordered, intelligible steps.
This idea is closely related to the logic of Catena.
In the game, two words are given. At first, they may appear to have almost nothing in common. The player does not know the complete path connecting them. Instead, the path is discovered step by step.
A → ? → ? → ? → B
Each intermediate word must form a meaningful link with the previous one, while also opening a possible route toward the destination.
The player therefore never needs to know the entire semantic space in advance. Only the next valid move is required.
This makes Catena more than a game of free association. Free association asks:
What does this word remind me of?
Catena asks a more demanding question:
What can I connect to this word that might also lead somewhere?
The difference is small in appearance but fundamental in practice.
A good Catena is not merely a sequence of associations. It is a path through a network of meanings.
Seen this way, Catena models a basic form of human thinking. We repeatedly encounter situations in which there is no direct route between what we know and what we want to understand. We proceed by finding intermediate concepts: an analogy, a metaphor, a shared context, a structural resemblance.
Scientific hypotheses often work this way. So do inventions, metaphors, design ideas, explanations and discoveries.
We begin at one point in a conceptual landscape and try to reach another.
We rarely possess a map of the whole landscape.
We only need to find the next meaningful step.
That is the philosophical premise behind Catena:
To discover a connection between two things, we do not need to know all the connections between all things. We only need to keep finding the right next link.