1.What is Say's law? What is Keynes' law?

Do neoclassical economists believe in Keynes' law or Say's law?

What are the components of the aggregate demand (AD) curve?

2.On a microeconomic demand curve, a decrease in price causes an increase in quantity

demanded because the product in question is now relatively less expensive than substitute products. Explain why aggregate demand does not increase for the same reason in response to a decrease in the aggregate price level. In other words, what causes total spending to increase if it is not because goods are now cheaper?