To attain the most worthwhile results from guppy breeding you need to adopt the scientific attitude. Every scientist is a doubter interested only in learning truth insofar as truth can be ascertained. He is trained to employ critical judgment. He is never bent on proving some statement or supposition of his own or another's; he is interested only in testing it. He often makes mistakes; is found by later research to be wrong. This he welcomes for he is trying to add to the sum total of human knowledge.
 The trained scientist has a mind which works in a fashion opposite to that of the lawyer. For example, one lawyer in court tries to prove one side of the case; the other the opposite. So they become trained in proving something. The scientist tests a proposition. He does not attempt to prove it right or wrong, but collects all the facts on both sides of the question, puts the "plus" facts in one column and the "minus" facts in another, and when he is finished, says, "All the facts I can find tend to show that this is the case." He does not care who originated some idea - George Washington could have first thought of it - he wants to know if it is true. He does not care whether hundreds of millions of persons in the past and a hundred million today believe acquired characters are inherited. He says, "Where's the proof?" Not until scientists doubted and questioned did flat earth become round, or a heavy weight and a light weight fall at the same speed. For hundreds of years everybody believed that a horse had thirty-six teeth and nobody dared doubt it until a person with a scientific mind opened a horse's mouth and counted forty-two.
 So, adopt the scientific attitude. Try not believing anything you have heard by authorities until facts satisfy you by indicating what they say to be true. Nor can you use what somebody said in place of facts. That is only opinion-some times nothing more than the result of hallucinations. Facts and figures live. Accumulate facts and figures! Write them down, discover new facts. A whole new world will open itself to you and you will have access to a happier and a fuller life.