The basis of the scientific theory starts with things like "it seems to me," or "I think that..." You then gather your impirical data and set forth testing to prove or disprove what you thought, logging data all the way down the line. Your subjective theories and thoughts are then confirmed or disavowed by the data you collected and you go on to the next level of decision making. I can't and won't believe any ENGINEER never says "I think" or "it seems to." Very few things in life or in science are absolute.