Does Language Shape Thought? From Philosophy to Neuroscience
Revisiting Wittgenstein with Neuroscience
Just as surely as no leaf is completely identical to another, so surely is the concept 'leaf' formed by arbitrarily dropping these individual differences [...] and now awakens the notion that there exists in nature, apart from the leaves, something that would be 'the leaf' - perhaps an original form according to which all leaves would be woven, drawn, measured, coloured, curled, painted [...]." (Nietzsche, 1873, p.880)
Ludwig Wittgenstein is regarded as a pioneer of linguistic philosophy and one of the most influential thinkers of the 20th century. His work initiated the "linguistic turn," a momentous shift from classical philosophy to a focus on language itself. His core idea is that language is decisive for our understanding of the world; indeed, it remains a focal point of philosophy to this day. According to Wittgenstein, no person, philosopher or otherwise, is capable of forming a single meaningful thought beyond the confines of words and sentences. This is captured in his famous statement: "The limits of my language mean the limits of my world" (Wittgenstein 1915-16, p.67).
Ultimately, Wittgenstein argues, there is no escape from this "cage" of language. It constitutes the only path to forming knowledge, perceiving the world, categorising it, and grasping thoughts. It would be utterly senseless to even attempt to consider anything outside of language. As he put it, "this running up against the walls of our cage is perfectly and absolutely hopeless" (Wittgenstein 1989, p.19). Our thoughts, therefore, are not free. When thinking in language, meanings do not float alongside the linguistic expressions, because, as Wittgenstein asserts, language itself is the vehicle of thought, the mirror of reality. It is both the tool and the vessel for our thinking. This means that everything that occurs in our minds, every thought, every insight, takes place in words and sentences and is thus constrained by the language we use.
This idea, however, was not Wittgenstein’s alone. Friedrich Nietzsche had already noted the discrepancy between language and reality, asking: "Do the designations and the things coincide? Is language the adequate expression of all realities?" (Nietzsche, 1873, p.878). His answer was no. Nietzsche had already grasped the thought that we only create images of facts but can never capture the facts themselves in mental constructs. He argued that when we invent a uniformly valid and binding designation for things, the "legislation of language" also provides the first laws of truth. This process is flawed from the outset, because, as Nietzsche states, "every concept arises from the equation of unequal things" (Nietzsche, 1873, p. 880). He concludes that the existence of so many languages proves that words are never concerned with truth or adequate expression. What, then, is truth? "A movable host of metaphors, metonymies, and anthropomorphisms. […] truths are illusions which we have forgotten are illusions ” (Nietzsche, 1873, p. 880 f.). Nietzsches solution? We must not let ourselves be guided by the logically thinking intellect, by the framework of concepts, but only by our intuition. And this intuition is in its essential core nothing other than the instinctive will to life or also the will to power. We must admit to ourselves. But I digress.
Wittgenstein himself later questioned his rigid stance. In his later work, he introduced the concept of "language-games," recognising that in everyday use, language is employed far more broadly than for merely describing facts. The meaning of words, he realised, is given by the specific contexts in which they are used, the everyday conversations among children, workers, theologians, and scientists. Each of these "games" follows its own rules, and every person participates in a multitude of them, profoundly shaping their perception and way of life. This means, while language is the vehicle of thought, this vehicle is modulated by a broader context. That means if we want to understand language we have to understand how it is used in specific social contexts. While this is not necessarily important for this article, I wanted to point out that Wittgenstein’s stance developed substantially in his later work.
From Philosophy to Science: The Sapir-Whorf Hypothesis
Now, building on Wittgenstein’s insights, one of the foundational ideas linking language and cognition is the Sapir–Whorf hypothesis. This hypothesis can be seen as an empirical extension of Wittgenstein’s framework, at least in my view. Whorf argued that our habitual use of language shapes how we perceive and interpret reality. The hypothesis exists in two forms: a weak version (linguistic relativity) and a strong version (linguistic determinism).
The strong version claims that differences between languages lead to equally deep differences in thought. In this view, if a language lacks a particular word or grammatical form, its speakers cannot fully grasp the corresponding concept. Grammar, structure, and vocabulary thus completely determine cognitive categories, resulting in worldviews that differ radically between languages. This largely aligns with Wittgensteins early works.
The weak version, by contrast, proposes a subtler link. It holds that language influences thought without entirely determining it. For example, speakers of different languages may attend to different aspects of reality depending on the structures and conventions of their language. In other words, language can channel attention toward certain features of experience while downplaying others.
Now, enough with theory.
To move this question from the realm of philosophical speculation to empirical investigation, we turn to the fields of psychology and neuroscience. How important is Language really?
The Empirical Evidence for Linguistic Relativity
Remembering early Wittgenstein, without language, thinking and understanding logically is "absolutely hopeless."
Research has indeed shown that different languages impose different grammatical and syntactic frameworks, which can influence what speakers notice and how they conceptualize the world (Slobin, 1987). For instance, in German, the word for bridge (die Brücke) is grammatically feminine, while in Spanish it is masculine (el puente). Such distinctions may subtly affect the mental representation of objects, even extending to broader conceptualizations, though this should not be overstated. "In many ways the language people speak is a guide to the language in which they think." (Hunt & Agnoli, 1991, p.377). Importantly, these differences may be largely implicit.
A more robust example comes from Boroditsky (2001), who studied how English and Mandarin speakers conceptualize time. English speakers typically represent time along a horizontal axis (left to right), while Mandarin speakers often use a vertical axis (top to bottom). In experiments, participants performed more accurately when reasoning about time in a spatial orientation consistent with their native language. This demonstrates that semantic "thought cages" can shape cognitive patterns. Notably, when speakers learn a new language, these differences diminish, suggesting that the influence of language on thought is flexible rather than rigid. This means language can indeed influence our thought processes, but through learning a different language we can alter this seemingly rigid system. This flexibility means the weaker form of Whorf's theory of linguistic relativity definitely holds merit.
For a long time it was hypothesized that this is only true for concepts that are directly dependent on language. For example, time is a construct, a human construct we embed in our thinking through using different words. Without language, time would be hard to conceptualize. For a long time colour perception was thought to provide a counterexample. It was thought that across languages, colour categories are largely universal, reflecting their evolutionary and perceptual salience. Unlike abstract constructs such as time, colour is directly observable, so linguistic variation should have limited impact on perception (Heider, 1972). But is this true? It turns out, not really.
Newer studies found that colour perception is also dependent on our language, specifically our vocabulary. Some languages have many words for colours, while others have only a few, "light" and "dark." Languages also differ in where they put boundaries between colours. While English uses the single word "blue" for many shades, Russian requires speakers to distinguish between light blue (goluboy) and dark blue (siniy). This constant linguistic practice sharpens their perception. Studies show that Russian speakers are measurably faster at discriminating between light and dark blue shades. This cognitive difference is also reflected in brain activity. When viewing colours shifting from light to dark blue, the brains of Russian speakers react as if a categorical change has occurred, while the brains of English speakers, who lack this linguistic boundary, do not register the same "surprise" (Winawer et al. 2007; Boroditsky, 2018).
The Limits of the Cage
However, language is not the sole determinant of cognition.
Regarding higher cognitive functions, research shows that language is not always the limiting factor for thought. Recent work argues that language functions primarily as a tool for communication, and while it is crucial as a medium for learning and memory, it is not indispensable for conceptual or mathematical reasoning (Fedorenko et al., 2003). Fedorenko et al. (2003) suggest that neural networks supporting functions like mathematical reasoning are distinct from language networks and that children with linguistic deficits, such as aphasia, do not necessarily show substantial impairments in non-linguistic thought tasks. Language, therefore, can be seen as a structural scaffold, a vehicle for organizing, transmitting, and retaining knowledge, rather than as the sole determinant of cognition!
