The laws of nature are the rules according to which the effects are produced; but there must be a cause which operates according to these rules. The laws of navigation never navigated a ship. The rules of architecture never built a house.
Thomas ReidIn every chain of reasoning, the evidence of the last conclusion can be no greater than that of the weakest link of the chain, whatever may be the strength of the rest.
Thomas ReidIn every case, we ought to act that part towards another, which we would judge to be right in him to act toward us, if we were in his circumstances and he in ours; or more generally - What we approve in others, that we ought to practise in like circumstances, what we condemn in others we ought not to do.
Thomas Reid