Medical Hypotheses exists to give ideas and speculations in medicine a fair hearing. Doing this is not easy. Most conventional journals would regard some of what is published here as questionable, most referees would reject it as 'unproven'. We have more liberal standards, for reasons we have presented before. But we still require 'good' science -- logical argument that is supported by fact and comes to interesting, even useful, conclusions. Alas, not everything received comes close to even this liberal standard. Since I joined the Editorial Board I have read about 130 submissions to Medical Hypotheses. They range from exciting and insightful papers that might be substantial advances in their field, to complete rubbish. I want to lay out what I believe to be the essence of the former so as to avoid having to read so much of the latter.