Until recently, it seemed impossible to learn a language without either ...
This does not fully line up with my experience learning languages, so I would like to see a source or evidence backing up this claim.
I know this is an anecdote, but I have learnt a significant amount of Japanese by just listening to podcasts, including on topics too abstract or too disconnected from me to have sensory experiences on, and I personally do not see why you can’t learn a language from nothing but the language itself.
This does not fully line up with my experience learning languages, so I would like to see a source or evidence backing up this claim.
I know this is an anecdote, but I have learnt a significant amount of Japanese by just listening to podcasts, including on topics too abstract or too disconnected from me to have sensory experiences on, and I personally do not see why you can’t learn a language from nothing but the language itself.
That sounds hard to believe if you knew zero Japanese before. (Inferring the meaning of unknown words from known words is different.)
Sure. If it were otherwise, deciphering the Voynich manuscript from the text alone would long have been achieved.