Rogative and Declarative

Russell isolates the Proposition from what he calls 'propositional attitudes', i. e. from the 'psychological' states that motivate the utterance of a proposition.  On that basis, it seems to follow that the Proposition does not reduce to the Proposal, or the Declarative sentence to the Rogatory sentence, contrary to what has been previously discussed here.  However, the very expression of thoughts in accepted symbols and structures can only be motivated by a desire to communicate them.  Hence, the very existence of a Proposition demonstrates that it is fundamentally a Proposal, and, likewise, that a Declarative sentence is essentially a Rogatory one.  So, regardless of his motives for publicly formulating it, Russell's distinction is like that of a hand from a wrist--analytically useful in some contexts, but insufficient as the basis of the thesis that a hand has autonomous existence, or of a critique of Biology.