«ولا شيء من النار ببارد بالإمكان العام»
And no fire is cold, in the sense of general possibility.
In the negative form, what is denied is the necessity of the corresponding affirmation. This does not mean every possible negative statement is always actually true. First identify the proposition's quantity and quality; then interpret the general possibility qualifying that negative judgment.
Affirmative general possibility: the negation is not necessary.
Negative general possibility: the affirmation is not necessary.
The “opposite side” is always relative to the affirmative or negative quality of the current proposition.