Concerning knowledge and perception derived directly from our own experience, none of us knows more substantially about them than men and women of other times and other places do, and perhaps much less. On the other hand, unlike personal knowledge as a result of direct experience, impersonal data accumulates from objective observation, inference records, hypotheses, theories related to them, and experiments conducted on them from generation to generation, and this type of non-experimental knowledge changes the nature of human experience, and all forms of life. on this planet, in ways that are hard to imagine, let alone fully realise.