"The whole truth"
In a court room one is required to present the truth, the whole truth, and nothing but the truth. This litany remains an excellent guide for anyone undertaking the job of making a genuine case against something or someone.
To make a case, whether scientific or criminal, one must present to an audience the truth, the whole truth, and nothing but the truth. In other words, one presents all relevant facts without distortion or deception: one presents the truth, and nothing but. We might testify in court, for example, that a defendant owned a gun that matched the bullet found in the victim, and then invite the appropriate conclusions about culpability to be drawn. Or we might report from the lab that experiments showed judicious application of our new wonder drug caused an abatement in a disease we hope to cure.
But this in itself is insufficient -- one must not leave out facts which are inconvenient to one's case. One may have footnotes and witness statements for everything we do report, but if relevant facts remain unreported, then the footnotes and witness statements are either cherrypicking, if intentional, or unfortunate, if inadvertent -- but the result in the end is that our report is worthless.
(By the way, to establish precisely which facts are relevant, it's helpful to fully understand the causal link between those facts of which we are aware -- just another reason that no explanation is complete without causality.)
Telling the whole truth means looking for facts that contradict one's argument, and then reporting them. If we know that on the night the victim died, for example, that the defendant spent the entire time in full public view at a function for police prosecutors, then it would be wrong to omit this fact from our testimony. If we know that not all our experiments have worked, and we are unable to explain the causality behind those that do or don't, then it would be wrong to say we know the whole truth, and dishonest not to seek a full explanation.
It's important to understand that if the omission of relevant facts is intentional, then being economical with the truth is the same thing as lying. If unintentional, then it begins to look like incompetence. If done repeatedly it begins to look like a modus operandi, and one is entitled to simply disregard intentionality, and simply ignore anything further from that quarter.
So to conclude: Honest reportage and honest scientific discussion represents the whole truth -- that is, all relevant facts. A report or discussion that ignores or fails to present all relevant facts is worthless. So too is a reporter or interlocutor who cherrypicks.
What prompted me to write this post today? Simple. Because Ian Wishart has a new book out.