But since this matter, not only new but also difficult, was perceived to be in many ways contrary to the opinion of the philosophers, lest something would be hastily and rashly published by someone in that university whose retraction would then be difficult and unseemly, my superiors ordered me to proceed cautiously and slowly, until the phenomenon itself had been corroborated by the experience of others, and not to stray casually from the trodden path of the philosophers without evidence to the contrary, and not to publish my observations in the letters to Welser under my name.