-  The ultimate source of discuss meant ‘smash to pieces’. It comes from discuss-, the past participle stem of Latin discutere, a compound verb formed from the prefix dis- ‘apart’ and quatere ‘shake’ (from which English also gets concussion and quash). Its literal meaning was ‘smash apart, break up’, and this gradually developed via ‘scatter, disperse’ to, in post-classical times, ‘investigate, examine’ and eventually ‘debate’. The apparently wide semantic discrepancy between ‘scatter, disperse’ and ‘examine’ was probably bridged by some such intermediate notion as ‘disperse or separate in the mind so as to distinguish and identify each component’. => CONCUSSION, QUASH
The Hutchinson dictionary of word origins. 2013.