the language of thought hypothesis

When we think, we think in words and sentences, which have meaning - and this mental language is 'mentalese':

The Language of Thought Hypothesis (Stanford Encyclopedia of Philosophy)

In its most basic form, the theory states that thought, like language, has syntax.

Language of thought hypothesis - Wikipedia

Here's a little video that explains it very clearly - and the English subtitles will help:

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Philosophy Phriday: Fodor's Language of Thought - YouTube

Or, as Chomsky says, thought comes before language:

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language of thought - YouTube

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