here

Aaron J. Powner, M.Ed.
High School Science Teacher

---

 You Are Here  |  home › courses › philosophy of science › degrees of certainty

sci·ence       /sī'əns/

etymology - circa 1300, "knowledge acquired by study," also "a particular branch of knowledge," from Old French science, from Latin scientia "knowledge," prp. of scire "to know," probably originally "to separate one thing from another, to distinguish," related to scindere "to cut, divide," from PIE root skei-. Modern sense of "non-arts studies" is attested from 1670s. The distinction is commonly understood as between theoretical truth (Greek episteme) and methods for effecting practical results (tekhne). In the 17th through 18th centuries this concept commonly was called philosophy. -- Online Etymology Dictionary, © 2012 Douglas Harper

 

DEGREES OF CERTAINTY

 

CERTAINTY

• Knowledge that has a degree of security from error
• Mental state of being without doubt

STATISTICS

• Branch of mathematics
• Statistical degree of certainty is the measure of how much confidence we have that an idea is true, expressed as probability
• Dependable ideas are subject to such statistical measurement.
• Examples can be found in many types of knowledge (politics, law, economics, science)

LEGAL DEGREES OF CERTAINTY

• Air of reality - only having the traces of truth
• Preponderance of the evidence - more likely than not
• Clear and convincing evidence - substantially more likely than not
• Beyond a reasonable doubt - no reasonable doubt can be raised
• Beyond a shadow of a doubt - no doubt can be raised

SCIENTIFIC DEGREES OF CERTAINTY

Hypothesis

• Ideas that propose explanations for natural phenomena (not just a guess)
• Based on repeated observations
• Must be testable by experimentation (empirical analysis of data)
• Hypotheses are seen as ideas that "might be true" because the data does not seem random or inconsistent

Theory

• Comprehensive explanations of important natural phenomena
• Supported by a large body of evidence gathered over time by many scientists performing repeated experiments
• Can be revised or rejected with new discoveries, but this is rare
• Theories are reliable predictive tools. This means they are powerful ideas that are seen as "probably true" because their statistical dependability is safe enough to use to solve real world problems, and they are reliable enough to create technologies that work most of the time.

Law

• Ideas that always work under the same conditions
• Laws are often the math equation part of theories
• Laws identify a cause and effect relationship in nature
• Does not propose explanation of natural phenomena, only predicts what will happen with 100% reliability
• A scientific law is a distillation of repeated observations and experimental results, stated as mathematical formulas
• May be true under a given set of circumstances, but not true outside of those constraints; therefore useful only within their restrictive definitions. Theories are often more useful in explaining phenomena than laws.
• Laws are seen as ideas that are "definitely true" under specific circumstances and are never wrong within those circumstances

PROBLEMS WITH CERTAINTY

• Correlation in data does not prove cause of phenomena
• We can misinterpret evidence
• Often, simpler theories explains data better - Does this mean that truth is always simple? (Occam's Razor states that "among competing hypotheses, the one with the fewest assumptions is more likely to be correct")

 

Internet Resources

Berkeley University Understanding Science Series

What is science?

How science works

What has science done for you lately?

Appendix: Scientific Law Topics

Compared to scientific theories, there are surprisingly few laws.

Conservation: mass, energy, and motion

Classical Mechanics: kinetic and potential energies of objects

Gravitation: relative motion of objects and apparent forces of attraction between them

Thermodynamics: exchange of heat between objects

Electromagnetism: energy fields around objects

Photonics: behavior of light

Quantum Mechanics: behavior of very small particles and tiny amounts of energy

Laws of radiation, chemistry, and geophysics are combinations of all the other laws at play in the world around us