Why is there a touch-move rule in chess?

Why is there a touch-move rule in chess? What is the purpose/logic behind it? or:Why is there a touch-move rule in chess? What is the purpose/logic be

Why is there a touch-move rule in chess? What is the purpose/logic behind it?

or:Why is there a touch-move rule in chess? What is the purpose/logic behind it?

Tags:rules,