Too little
Settling on the first account
“The reading rose, so our explanation is right.”
One observation is treated as decisive even though a rival account could produce it.
Discernment
Ask what the evidence actually distinguishes.
A disposition to distinguish what is sound from what merely seems convincing.
Discernment weighs the connection between an observation and a claim. A result can be genuine yet support less than a persuasive explanation suggests. Scientific discernment asks which alternatives remain possible and what would tell them apart.
Discernment gives a better test of the claim
The thermometer rises when the reading lamp is switched on. Is the room warming, or is the instrument responding to a local source of heat? The rising number fits both accounts. You stop admiring its precision and ask what comparison would distinguish them. The lamp has become a suspect rather than a decoration.
Finding the balance in Discernment
A rising thermometer reading has two plausible explanations: a change in ambient conditions or local heating from a nearby lamp.
A fitting response
Comparing explanations
“What comparison would let these two accounts predict different results?”
You seek information that separates the alternatives rather than more repetitions of the ambiguous reading.
Pursued too far
Demanding impossible certainty
“Every measurement has limitations, so none can tell us anything.”
Relentless suspicion can erase meaningful differences in the strength of evidence.
Evidence becomes informative through the alternatives it helps distinguish, not through its impressive appearance.
What Discernment makes possible
Discernment helps you spend effort where it can change understanding. Instead of collecting more of the same ambiguous result, you can seek a comparison that answers the disputed point. It also improves reading: the strongest-looking graph is not always the one that bears most directly on the question.
Discernment in ordinary life
Two things change together
A graph shows two trends. Ask what else changed before deciding that one explains the other.
A confident abstract
Read how the result was obtained and which claim it supports before borrowing the conclusion for a different situation.
Nearby virtues, different work
Exactitude
Exactitude preserves the number and conditions. Discernment asks what conclusion those particulars warrant.
Open-Mindedness
Open-Mindedness admits competing explanations; Discernment evaluates how well the evidence separates them.
Discernment and its counterfeits
Counterfeit Discernment: automatic debunking
Finding a limitation in every account can feel perceptive while avoiding comparison of their merits. A discerning judgment says what remains supported.
How to cultivate Discernment
Separate the observation from the interpretation in your notes.
Name a plausible alternative explanation.
Ask what available evidence bears differently on the alternatives.
Try it today
Choose a modest claim in something you are reading. Identify its evidence and one question about how that evidence supports the conclusion.
Questions worth returning to
- What else would produce this observation?
- Which uncertainty would a useful comparison reduce?
Quotations and further reading
Seven selections to return to through the week. Follow a source link to read the surrounding passage.
The circumstances, then, which accompany any observed fact, are main features in its observation, at least until it is ascertained by sufficient experience what circumstances have nothing to do with it, and might therefore have been left unobserved without sacrificing the fact.
John F. W. Herschel · Preliminary Discourse on the Study of Natural Philosophy · § 111
Herschel gives surrounding conditions evidential weight. The lamp’s position belongs beside the thermometer reading until there is reason to treat it as irrelevant.
Comparison, without contrast, does not amount to anything logically.
John Dewey · How We Think · Chapter Seven
Dewey’s surrounding examples vary conditions rather than simply repeat similar cases. The useful comparison is one that helps reveal which difference matters.
According to it, light travelled faster in water than in air; according to the Undulatory Theory, it travelled faster in air than in water.
John Tyndall · Fragments of Science · Vol. II, III. On Prayer As A Form Of Physical Energy.
Tyndall contrasts the predictions of emission and wave theories of light. The useful comparison is one on which rival explanations give different answers, as the two proposed causes of the thermometer reading do.
… it is not the direct evidence of our senses that we are in any case called upon to reject, but only the erroneous judgments we unconsciously form from them, …
John F. W. Herschel · Preliminary Discourse on the Study of Natural Philosophy · § 71
Herschel distinguishes a sensation from the conclusion attached to it, then asks for counter-evidence. The warm thermometer reading can be accurate even when the inference about the whole room is mistaken.
So that here a belief—if indeed a statement with no definite idea attached to it can be called a belief—had spread over almost the whole of England without any vestige of evidence.
Charles Darwin · The Autobiography of Charles Darwin · Written May 1, 1881
Darwin traces a story about beans to informants unable to explain what they meant. Repetition supplied apparent authority while the observation itself remained missing.
Although the method described is sufficiently accurate for finding the parallax of an object as near as the moon, it will not answer for the sun, which is so remote that the smallest error in observation would lead to a false result.
Mary Somerville · On the Connexion of the Physical Sciences · Section VII.
Somerville shows that a method’s adequacy depends on the question and scale. A useful measurement in one setting need not warrant the same confidence in another.
If we construct a theory based on a number of hypotheses, and if experiment condemns it, which of our premises is it necessary to change? It will be impossible to know.
Several assumptions can make a failed prediction hard to interpret, Poincaré argues. Identifying what a test distinguishes is part of designing a useful next question.
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Practice this collection
Choose this approved collection as an optional workbook program, or select individual virtues in My Virtues.