How can you approach an argument for which you have no direct evidence?

Answer 1

If we look at astronomers, they approached "an argument" through using theories. A theory is an idea, an educated guess gained from observations, experience, and an ability to challenge usually accepted thinking. So, early thinkers challenged and hypothesized:

1. the earth was not flat
2. the earth revolves around the sun
3. there were 9 planets
4. only recently, in 2006, Pluto was reclassed -- challenging the usually accepted thinking!
5. rain ultimately comes from / begins with the oceans (water cycle)
6. climate warming exists
7. humans cause most of climate changes

So think about what your theory might be if you have no direct evidence. Back up your theory with your ideas of what the facts might be-- IF you could get to any direct evidence.

An example:

Do you think earthworms live below the soil layer?

You cannot dig to the center of the earth, so you cannot prove that earthworms don't live in the earth. You know earthworms like soil. They break down debris to make soil.

You know there is rock below soil. (bedrock) You know the inner core of the earth is hot.

Your theory: Earthworms cannot live in rock beneath the soil layer because that area would not give them food and water they need to survive. If the living environment is too hot, earthworms would shrivel and die just like when they stay too long on a sidewalk on a hot day.

Now, expand on your theory, giving ideas you have about why earthworms would only live in Earth's soil layer.