Which monetary theory (Keynesian or Monetarist) is most effective?

According to Keynesian, given an increase in the supply of money, the interest rates
reduces and this stimulates borrowing as well as spending shifting the demand curve towards the
right and consequently increasing the real GDP. The impact of this change or monetary policy
depends on the range of the aggregate supply curve. Keynesian emphasizes the role played by
fiscal policy in stabilizing the country's economy.
Monetarists, on the other hand, believe that a change in the supply of money is based on
the predictable and direct impact on the economy as postulated in the quantity theory of money.
Monetarists hence emphasize the importance of maintaining and controlling money in supply in
order to control or regulate inflation. They are always critical of the expansionary fiscal policy
since it causes crowding out and inflation.
I believe the government should always control the economy when things spiral out of
control such as inflation hence Keynesian theory makes sense. The government should also
increase its spending in order to control or compensate for the decline in aggregate demand. The
government spending would, in turn, boost the overall productivity and protect jobs which
eventually drives consumption and spending. Although control of money supply is essential,

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government intervention is equally important. A troubled economy can otherwise spiral
downward unless the government intervenes with its fiscal policies which drive consumers to
buy services and goods.
Through the change in government expenditure and consumption as well as net exports,
the state of the economy can be changed. It's clear that in times of recession, expansionary fiscal
policy can, in turn, regenerate the economy. This should force governments to borrow more in
order to offset the fall in consumer spending.