What are the arguments for and against the classifications of viruses as living organisms?

Answer 1

Viruses are not living organisms. They do not fit the current scientific description of a living organism.

Against
Viruses are not living organisms because:

• They are incapable of synthesising proteins without a host cell
• They cannot replicate their genetic information without a host cell
• Viruses and prions have more in common than viruses and cells do. Prions are not alive
• They do not respire or feed
• They are not able to move themselves
• They can't communicate with each other or sense their environment
  
• Our current definition of life does not support viruses as living organisms.
  

For

• They contain their own, unique proteins and the genetic information necessary to produce them
• They do produce proteins and replicate themselves when provided with the necessary machinery by a host cell
• One could also argue that bacteria or even animals are simply replicating collections of molecules and therefore aren't alive either
  
• Our current definition of life is incorrect.

In short, viruses are blueprints just like DNA. They contain information that can lead to its replication, but need help to get there, and as such aren't alive. They are simply a collection of molecules that seem to be life-like when they are mixed with a host cell.

Answer 2

Viruses are ambiguous, they are something like living organisms and something like toxic chemicals. On the whole, the predominant opinion is that they are living.