Sentence:  Furthermore, we seem to derive some assistance from the special nature of acts saying something by contrast with ordinary physical actions: for with these latter even the minimum physical action, which we are seeking to detach from its consequences, is, being a bodily movement, <WSD>in pari materia</WSD> with at least many of its immediate and natural consequences, whereas, whatever the immediate and natural consequences of an act of saying something may be, they are at least not normally other further acts of saying something, whether more particular on the speaker's own part or even on the part of others. 
Meaning of the word marked with <WSD> tags:  Dealing with the same matter or subject.