Final answer:
The Classical Viewpoint in economics includes the Keynesian perspective, which advocates for government intervention, and The Neoclassical Perspective, which believes in the economy's self-adjustment in the long run.
Step-by-step explanation:
The two theories under the Classical Viewpoint in economics are the Keynesian perspective and The Neoclassical Perspective. The Keynesian perspective emphasizes the role of government intervention and the use of fiscal and monetary policy to manage economic cycles and mitigate the effects of recessions. On the other hand, The Neoclassical Perspective stresses that in the long run, the economy will self-adjust back to its potential GDP level of output through flexible price levels and that economic participants have rational expectations.