2. Is there any certainty that they will stand unchanged forever?
3. Under what circumstances are such changes made?
4. Can you cite any accepted laws or theories of past periods which have been overturned?
Deductive Reasoning. After general laws have been established, either by human experience or accepted inductive reasoning, they may be cited as applying to any particular case under consideration. This passing from the general law to the particular instance is deductive reasoning. Deductive reasoning has a regular form called the syllogism.
Major premise. All men are mortal.
Minor premise. Socrates is a man.
Conclusion. Therefore, Socrates is mortal.
If the three parts of a syllogism are correct it has absolute convincing power. Most attempts to disprove its statement attack the first two statements. Although it carries such an air of certainty it is likely to many errors in use. An error like this is common:
All horses are animals.
All cows are animals.
Therefore, all cows are horses.
Explain the fallacy in this syllogism.
Quite as frequently the incorrect syllogism is of this kind.