Teachers may not tell students to go out and shoot the president. "Hate speech" is also prohibited: a teacher does not have the right to spout racial slurs.
This is a great example of why general statements are not always true since teachers do have the right to express themselves in a classroom it does not mean they have the right to be telling students "hate speech".
If there is an exception that the argument hasn’t accounted for, that may point us to a weak spot that we should mention in our assessment. Often, a particular claim or reason may sound plausible, but we need to slow down and ask if it is true in all cases. For example, take the following argument:
This comes to show that general statements does not make them entirely true.
“We cannot do without it
This does not really specify. This is an example of equivocation.