Daphne's Virus Argumentation

When attempting to define whether or not viruses are living creatures, it is important we consider what it truly means to be alive. In order to qualify as a living, a being must possess all of the following characteristics:

1. Living things are composed of cells
2. They possess different levels of molecular/cellular organization
3. They take in energy to use for maintenance and/or growth
4. They respond to stimuli presented by their environments
5. They reproduce, sexually or asexually
6. They experience growth
7. They adapt to their environment over time (as a species) through evolution

Because of these standards, viruses cannot be considered to be alive. When scientists crystallized the tobacco mosaic virus, they determined that the virus lacked the genes for metabolism. This indicates that they do not take in energy for maintenance and/or growth. Since it takes just one of these qualities being absent to disqualify something from being alive, viruses cannot be considered living. Furthermore, viruses cannot reproduce on their own.  When not in contact with a host cell, viruses are no more active than free organic matter. In this state, they are inactive and no internal biological activities occur within the virus. Viruses consist of no more than membrane-bound DNA or RNA. Only when they infect a host cell are they able to multiply and divide through the lytic cycle. In order to be alive, organisms must be able to reproduce on their own. Also, viruses do not respond to stimuli in their environments, which is another factor required for living creatures.
People (especially scientists) like to create organized categories and imagine that all of the world fits into them, checking off all the boxes. Such is not necessarily the case with viruses. They almost straddle the definition of life, seeing as they do not check off some of these qualifications. However, they seem to possess lifelike qualities, which is what makes classifying them so difficult. As far as classifying them by the preset standards established by scientific laws, viruses are most definitely not alive.