Language has come to take a central place in Twentieth-century analytical philosophy. It’s as though language became the lens through which we inspect thought and discover truth. I’m not saying that thought is where truth resides, but rather that the expression of thought is what reveals truth. We can’t put people in scanners that will reveal their thoughts so we can assess if they are true or false. Even if we could, it’s not clear that this would become a fundamental methodology. Why? Because figuring out philosophical truth isn’t a descriptive or empirical project, as would be, for instance, the observation of stars in the universe. Yet, we engage in philosophical enquiry with thought, and we develop it in language.

Since so much of what we know and learn depends on language, it is no surprise that language use is very important. For instance, it matters whether the commandment that "you shall not kill" is about killings or murders. What we mean by the commandment is very important, and what we mean depends on how we think about it and express it in language. Thus, language has taken centre stage in philosophical investigation.

Now, what about logic? The same reasoning applies: logical reasoning is expressed in language, and language use is crucial to understanding logical reasoning. Yet, there’s a difference between studying language use as a proxy for logical reasoning and exclusively studying language to ground logic.

Here’s the thought I want to get at. While language is important to logical reasoning and speech acts reveal a lot about logic, the specific words we use are rather inconsequential, as is the language (e.g., English, French) that we know and use. Indeed, it’s conceivable that what is central in a speech act that reveals reasoning is the goings-on at the level of thought behind the linguistic expression. But if logic is grounded in language, and language only reveals the thought process, doesn’t it follow that logic is grounded in thought? And if so, isn’t the study of language really the study of human psychology? And if so, doesn’t this ultimately ground logic in psychologism?