It's not so absurd. How do we know solipsism isn't true? Because of two reasons, (1) the physiology of others is similar to our physiology, and (2) we can see e

It's not so absurd. How do we know solipsism isn't true? Because of two reasons, (1) the physiology of others is similar to our physiology, and (2) we can see evidence of inner state reflected in behaviour. For dogs we can make a similar argument using (1) and (2). It is slightly weaker than applying it to other humans but not by much. Searle's comment pertains to (2).