treasons, stratagems and spoils

quoting Shakespeare’s The merchant of Venice, act 5, scene 1 :
‘The man that hath no music in himself, / nor is not moved with concord of sweet sounds, / is fit for treasons, stratagems and spoils; / the motions of his spirit are are dull as night, / and his affections dark as Erebus: / let no such man be trusted.