Describe Keynes' criticism of Say's law in a money economy

In order for Say's law to hold in a money economy, any decrease in saving would have to be offset by an equal increase in investment. According to the Classical economists, this would happen through changes in interest rates. Keynes disagreed with this view and pointed out that added saving would not necessarily lead to an equal amount of added investment. Keynes asserted that people save and invest for a variety of reasons, and not on one single variable such as interest rates. According to Keynes, saving is more responsive to changes in income than to changes in the interest rate, and investment is more responsive to change in technology and business expectations than to changes in interest rate.