Reducing Terms
Sometimes a syllogism that is apparently fallacious because it is stated with more than three terms can be translated into an equivalent, valid three term syllogism. For example:
- Major premise: No humans are immortal.
- Minor premise: All Greeks are people.
- Conclusion: All Greeks are mortal.
This EAE-1 syllogism apparently has five terms: "humans", "people", "immortal", "mortal", and "Greeks". However it can be rewritten as a standard form AAA-1 syllogism by first substituting the synonymous term "humans" for "people" and then by reducing the complementary term "immortal" in the first premise using the immediate inference known as obversion (that is, "No humans are immortal." is equivalent to "All humans are mortal.").
Read more about this topic: Fallacy Of Four Terms
Famous quotes containing the words reducing and/or terms:
“Single acts of tyranny may be ascribed to the accidental opinion of a day; but a series of oppressions ... too plainly prove a deliberate, systematical plan of reducing us to slavery.”
—Thomas Jefferson (1743–1826)
“As for the terms good and bad, they indicate no positive quality in things regarded in themselves, but are merely modes of thinking, or notions which we form from the comparison of things with one another. Thus one and the same thing can be at the same time good, bad, and indifferent. For instance music is good for him that is melancholy, bad for him who mourns; for him who is deaf, it is neither good nor bad.”
—Baruch (Benedict)