Sufficient vs Necessary

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• 3 Likes

  nicholas.leon96 Alum Member

  September 8 edited September 8 224 karma

  NA must be true for the argument to hold any water at all, SA makes the argument valid. NA are usually very weak compared to SA, things that you might take for granted.

  Example of NA:
  If the weather is good tomorrow, we will catch lot of fish at the lake
  The weather will be good tomorrow
  Therefore, we will catch lots of fish
  A necessary assumption here would be that there are even fish in the lake to begin with! Something so subtle that you could honestly pretty reasonably assume to be true without it being stated out right.

  Whereas SA questions are something that makes the conclusion valid. I like to think about it as we have conclusion Y, we need to find answer choice X that works as a sufficient assumption to trigger the conclusion, in other words X->Y where X is the answer choice and Y is the conclusion in the stimulus.

  Example:
  The weather will be good tomorrow
  We will catch lots of fish tomorrow
  Sufficient assumption: if the weather is good tomorrow, we will catch lots of fish

  I hope this helps!
• Ben Udeze Core Member

  September 8 3 karma

  Great Explanation!