Without descending fully into epistemology, I tend to think that there is no proper "idea" in your head before it's phrased in language - the act of initially describing something in natural language *is* the act of generating it.
Are you saying it's impossible to program without first formulating a natural language sentence? That sounds dubious at the very least.
Research on LLMs suggest that's probably not the case. See the work on reasoning in latent space, and on shared concepts between languages being represented independently of the individual language.
Of course one might argue that even if LLMs are capable of ideation and conceptualisation without natural language, doesn't mean humans are.
But the fact that up to 50% of people have no inner monologue seems to refute that.