We agree with the target article that assuming language-of-thought (LoT) is useful for the development of cognitive and developmental theories. We note that the target article is weak in its assumptions about development of LoT and possible existence of multiple LoTs. In response to these weaknesses, we outline several developmental principles for LoT development, showing how a developmental theory of LoT springs from probabilistic LoT. We suggest a system 1.5 of reasoning allowing interchange between Bayesian and logical rules as it fits purposes or domain.