Define a term by genus and difference: Grammar, Round 1

1 Learn

You will be able to

Name the genus and the differentia in a given definition.
Test a definition for being too wide (it admits what it should not) or too narrow (it excludes what it should admit).
Tell a definition from a description and from an example.

LibraryObserve, Define, Represent: The First Three Moves · Definition: what exactly do we mean?Aristotle's form of definition, the genus and then the differentia, and why using a word fluently is not yet defining it.2 min glance · 6 min
LabDefinitionsDefinition as a boundary-stone, with a test: admit everything it must and exclude everything it must not. A definition is not a description or an example.
LibraryThe Seven Liberal Arts, Hands-On: Logic, Proof and the Quadrivium · Three teachers of methodSocrates in the Euthyphro: ask what the word means before arguing about the thing.2 min glance · 6 min
LibraryAugustine on Signs, Interpretation and Eloquence · Things and signsWords are conventional signs, so before you judge a claim you must know what its words stand for, and for whom.2 min glance · 6 min

2 Practise

Answer each card from memory, then grade yourself honestly. The cards join your review deck and come back just before you would forget them.

recall
What does the Greek ὅρος, the root of ὁρισμός ("definition"), literally mean, and what does that suggest about defining a word?

Show answer
It means a boundary-stone, the marker set at the edge of a field. To define is to say where a word stops.
recall
What is an operational definition, and how would it sharpen the word "slow"?

Show answer
Following Bridgman, it defines a concept by the operations used to measure it. For "slow", it asks: slower than what, measured where, for which users?
explain
How does William James's squirrel example show that some disputes are verbal?

Show answer
Both sides agree on the facts: the man passed north, east, south and west of the squirrel, but never in front of it, to its right, behind it and to its left, since it kept turning to face him. They differ only on what "going around" means, so once that is fixed, nothing is left to dispute.
recall
What is the elenchus, and what habit does the page say to take from it?

Show answer
The elenchus is Socrates's method of testing a claim by asking for definitions and drawing out consequences. The habit to take is to ask what the word means before arguing about the thing.

3 Prove it: the mastery check

5 questions drawn from a pool of 12. The pass mark is 80%. There is no time limit, and you can retake it with new questions; your best result counts.

4 Prove it: the performance task

Define three ordinary terms and test them

Choose three ordinary nouns from a published text, such as a manual, a rule book or a news report. Do not choose names of people. For each term: (1) write a one-sentence definition that names the genus and the differentia, and mark which is which; (2) list three cases the definition must admit and two it must exclude, and check each one against it; (3) find one case near the boundary, say whether the definition admits it, and judge whether the definition is too wide, too narrow or right on that case; (4) revise the definition once and show what changed. Then write one line on why a list of features or a few examples would not do the same job. Allow about 30 to 45 minutes.

What to hand in: A one-page table of the three terms, each with its definition (genus and differentia marked), the cases tested, the boundary case and its verdict, and the revised definition. Save it on the page or download it.

Check your work against the rubric Each definition is one sentence that names a genus and a differentia, and both are marked. Each term is checked against at least three cases it must admit and two it must exclude, and the result for each case is written down. Each term has a boundary case with a verdict of too wide, too narrow or right, and the verdict follows from the case. Each revised definition repairs the fault that the cases found, or the write-up says why no repair was needed. The closing line tells a definition apart from a description (a list of features) and from an example (one instance).

Your work Or a link to it (optional)

Saved only in this browser. To keep a copy, download it or export your progress.

5 Discuss: the seminar

Read the text, then think, write or talk through the question with someone. There is no answer key: the aim is a better question.

Grammar · Round 1

Augustine of Hippo, Confessions, I.8.13 (Book I, chapter 8, section 13)J. G. Pilkington's translation (Nicene and Post-Nicene Fathers, First Series, vol. 1, 1887), public domain, as revised for New Advent. Read the whole of section 13, where Augustine describes how he learned to speak.
Dionysius Thrax (attributed), The Art of Grammar, sections 12 to 25 in Davidson's numbering (12 the word, 13 the sentence and the list of eight parts, 14 noun, 15 verb, 19 participle, 20 article, 21 pronoun, 23 preposition, 24 adverb, 25 conjunction)Thomas Davidson's 1874 translation, 'The Grammar of Dionysios Thrax' (Journal of Speculative Philosophy 8, pp. 326-339), public domain. Davidson thought the work genuine, but its authorship is now disputed: Vincenzo Di Benedetto argued in 1958 and 1959 that only the opening sections go back to Dionysius (2nd century BC) and that most of the rest, including the parts of speech, was written in the 3rd or 4th century AD. Leading scholars at first rejected his argument, but it is now widely accepted by specialists (status: Provisional, taken from a general reference summary and not checked against Di Benedetto's papers). Read it as the short school grammar that shaped later Greek and Latin teaching, not as the certain work of one author. Other editions number the sections differently.

Augustine says he learned to speak by watching which things his elders named and moved towards, and by reading their faces, glances and tones. Dionysius sorts the words of a sentence into eight kinds. What does each account assume a word is, and which of the two explains better how a child first learns what a word means?

Augustine says he gradually gathered what things words were the signs of. Are all eight of Dionysius's parts signs of things, or do some, such as the article and the conjunction, do a different job?
Dionysius defines a noun as a declinable part of speech signifying something concrete or abstract (section 14). Is 'nobody' a noun by that test, and what does the test miss?
Augustine's account suggests that a child learns a name by seeing an elder say it and move towards the thing. What is left to learn after that, and who must already know what?

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Define a term by genus and difference