Dogs are dogs.  They are not people in doggie suits.  Yes, at times, they seem to be almost human but they are dogs and they think like dogs nevertheless. 

For example, when dogs feel stressed they take the edge off by chewing objects.  Chewing makes them feel good and helps relieve anxiety.  When dogs are destructive it is because they feel anxious or abandoned for whatever reason and they have found a way to relieve those feelings.  They have no idea that their stress-reliever is your brand new sofa.  They don't have monetary values and the dining room table leg works just as well as a stick found in the back yard.

It is important to shape this behavior in a positive way by providing appropriate chew items and placing the dog in an area where it cannot damage your home and its contents when you are unable to supervise it.  Likewise, while the dog is learning what is appropriate to chew on it is important that you keep shoes, socks, children's toys, etc. out of its reach.

Did you know that dogs have the mentality of a two-year-old child?  Would you leave a two-year-old child unattended?  Of course not.  So, like a two-year-old child,  your dog needs to be protected from what can harm it when you are not able to supervise it. 

As dogs mature they "earn their honor," so to speak, by learning what is appropriate to do.  Eventually, most dogs get to a place where they can be trusted not to damage items when they are not being supervised.  However, some dogs never get to this point and they need to be confined in a safe area when you leave the house right into old age.  

Another thing to consider is the dog that suddenly begins to act out in inappropriate ways.  Dogs just do not "suddenly" do anything.  There are always outside factors that influence a dog's behavior.  For example, your normally well-behaved dog "suddenly" starts damaging things while you are at work.  Ask yourself what has changed in the dog's environment that could cause the dog to stress.  Was there a thunderstorm while you were gone?  Have you had to work longer hours?  Has anything in the home dynamics changed?  Don't just assume that your dog is getting even with you for whatever reason.  Dogs are simply not capable of diabolic thinking.  They are basic act and react creatures.