[211] Surely not, we must then explain what it is which he intends to signify. All the lessons and all the admonitions of instruction are built up and established on the nature which is calculated to receive instruction, as on a foundation previously laid; but if there is no natural foundation previously in existence, everything is useless; for men, by nature destitute of sense, would not appear at all to differ from a stock or a lifeless stone; for nothing could possibly be adapted to them so as to cleave to them, but everything would rebound and spring back as from some hard body.