The opposite of a logical fallacy is a logical argument or valid reasoning.
A logical fallacy occurs when there is a flaw in reasoning that undermines the logic of an argument. This can manifest in various forms, such as making unwarranted assumptions, drawing invalid conclusions, or misrepresenting information.
On the other hand, a logical argument is one that is structured in a coherent way, where the premises lead to a sound conclusion. This means that the reasoning process is clear, grounded in evidence, and follows established logical principles. In essence, while a logical fallacy leads to incorrect conclusions, sound reasoning establishes a solid foundation for arriving at accurate and valid conclusions.