Question about Negating Conditional Statements

Comments

• equallyyoked Alum Member

  July 2023 474 karma

  This is a good question. I thought the negation test did not always work for conditional statements.
• Clemens_ Live Member

  July 2023 edited July 2023 299 karma

  'Not all A's are C's' and 'Some A's are not C's' mean the same thing, they aren't negations of another. For example, if I say 'Not all apples are green,' this means the same thing as 'Some apples are not green.'

  Now, how do we negate a statement like this? If I say, 'Some apples are not green,' I maintain that there are in fact apples in colors other than green. So negating this would be, 'It is not the case that there are apples in colors other than green,' or simply, 'All apples are green.'

  There also is a Wikipedia article on this subject, though it is a little on the technical side of things: https://en.wikipedia.org/wiki/Square_of_opposition