323. [315] But the things which we have hitherto said concerning degrees and atmospheres are, for the most part, theoretical; but all theoretical things should be drawn and concluded from the facts of experience, and also be confirmed by them. For unless the facts of experience, as it were, lead the hand of man in coming to conclusions, he may be deceived in theoretical things, and from some imaginary hypothesis, be carried away into false principles entirely opposed to what is true, which he can then confirm by fallacies and appearances of every kind; for false principles may be confirmed by appearances and fallacies to such a degree, that a man may believe that they are truths themselves. I wish, therefore, now to produce some facts of experience, by which not only what has been said may be confirmed, but also by which everyone who is in the light of the mind or who has natural ability, may draw conclusions as to many other things.