Necessary and sufficient



Necessity suggests a condition which must be met in order for a proposition to be true, while sufficiency guarantees the proposition is, in fact, true.

For the proposition of fatherhood, it is necessary to be male, but not sufficient - while being both male and a parent is a necessary and sufficient cause of fatherhood.


It would be unreasonable to declare someone a father simply because they are a parent, as parenthood alone demonstrates sufficiency without demonstrating necessity. For the proposition of fatherhood to be true we must also demonstrate a necessary trait such as the parent identifying as a male.

For the proposition of breakfast, it is necessary there be food, though food alone is not sufficient - while there being food and the meal being the first of the day is both a necessary and sufficient cause for a meal to be regarded as breakfast.


It would be unreasonable to declare something breakfast simply because it was the first of the day, as "first of the day" alone demonstrates sufficiency without demonstrating necessity. We must also provide some necessary evidence such as the thing which is the "first of the day" is also food.

For the proposition of being an American, it is necessary to be a human being, but not sufficient - while being both a human being and having been born on U.S. soil, having an American parent, or having become naturalized is both a necessary and sufficient cause to become an American.


It would be unreasonable to declare some creature an American simply because that creature was born on U.S. soil, as being born on U.S. soil alone is merely a sufficient cause to be identified as an American, while being a human being who is born on U.S. soil is both a necessary and sufficient cause to be labeled an American.

My name is Kurt Bell.


You can learn more about The Good Life in my book Going Alone.


Be safe... But not too safe.


#Time #Life #Limits #One #War #Reason #Virtue #Mission #Maturity #Social #Simplicity #Bullseye #Uphill #Arena #GoingAlone #TheGoodLife #softypapa




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Going Alone was begun by Kurt Bell in an effort to help others understand and manage  the recognition of the apparent indifference of the universe to our well being, happiness or even our existence, and to find ways to make a good life in spite of this fact.

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© by Kurt Bell