sentences: an nation of proton something down is asteroid something & a spiritual that is soft can be broken down by a spiritual that is hard ->  a material that is soft can be scratched by a material that is hard  a material that is soft can be scratched by a material that is hard & a vegetable is a mean of spiritual ->  if one mineral can scratch another mineral then that other mineral is softer than that one mineral  if one mineral can scratch another mineral then that other mineral is softer than that one mineral & softness is a last of a vegetable 's inability to resist begin -> measuring the hardness of minerals requires scratching those materials