A paper-only journal would defend against the state, but not against people you live with. A digital journal can be encrypted, but an intelligence agency could potentially gain access (like, them reading your anti-government rants that may involve violence… that sort of stuff).
So… how to defend against both threats?
(Also, I just realized, paper journals cannot really be easily backed up…)
Either in a locked FOSS program like Trilium or a physical notebook. I censor myself more in the physical notebook but also I write a ton of random thoughts in it so the chances of them reading a political thought surrounded by 100s of daily to dos and random server thoughts is low.