Page:Popular Science Monthly Volume 13.djvu/488

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THE POPULAR SCIENCE MONTHLY.

probability, or as a fair guess, that this handful was taken out of that bag. This sort of inference is called making an hypothesis. It is the inference of a case from a rule and result. We have, then—

Deduction.
Rule.—All the beans from this bag are white.
Case.—These beans are from this bag.
ThreeDots.svg Result.—These beans are white.
Induction.
Case.—These beans are from this bag.
Result.—These beans are white.
ThreeDots.svg Rule.—All the beans from this bag are white.
Hypothesis.
Rule.—All the beans from this bag are white.
Result.—These beans are white.
ThreeDots.svg Case.—These beans are from this bag.


We, accordingly, classify all inference as follows:

 
 
 
Inference.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Deductive or Analytic.
 
 
 
 
Synthetic.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Induction.Hypothesis.

Induction is where we generalize from a number of cases of which something is true, and infer that the same thing is true of a whole class. Or, where we find a certain thing to be true of a certain proportion of cases and infer that it is true of the same proportion of the whole class. Hypothesis is where we find some very curious circumstance, which would be explained by the supposition that it was a case of a certain general rule, and thereupon adopt that supposition. Or, where we find that in certain respects two objects have a strong resemblance, and infer that they resemble one another strongly in other respects.

I once landed at a seaport in a Turkish province; and, as I was walking up to the house which I was to visit, I met a man upon horseback, surrounded by four horsemen holding a canopy over his head. As the governor of the province was the only personage I could think of who would be so greatly honored, I inferred that this was he. This was an hypothesis.

Fossils are found; say, remains like those of fishes, but far in the interior of the country. To explain the phenomenon, we suppose the sea once washed over this land. This is another hypothesis.

Numberless documents and monuments refer to a conqueror called Napoleon Bonaparte. Though we have not seen the man, yet we can