Nevertheless, if instead of adhering to the impressions of their senses and to those of certain false or deluding experiences men would insist strongly upon this single notion of the pure mind, namely, that it is not possible for a body that is only slightly agitated to produce a violent motion in another body since it cannot communicate more speed to the body it strikes than it has in itself, it would be simple to conclude from this alone that there is some subtle and invisible matter that is violently agitated and is generally spread throughout all bodies, and to conclude many other similar things that would enable us to know the nature of fire, and that we could also use to discover many other more hidden truths.