have not this resource, we seek to extend our knowledge by the help of reasoning. Starting from facts known to us from the documents, we endeavour to reach new facts by inference. If the reasoning be correct, this method of acquiring knowledge is legitimate.
But experience shows that of all the methods of acquiring historical knowledge, reasoning is the most difficult to employ correctly, and the one which has introduced the most serious errors. It should not be used without the safeguard of a number of precautions calculated to keep the danger continually before the mind.
(1) Reasoning should never be combined with the analysis of a document. The reader who allows himself to introduce into a text what the author has not expressly put there ends by making him say what he never intended to say.
(2) Facts obtained by the direct