[Guderian]

The failure of Lamarks theory is already taught. Well, I remember hearing about it. I think failed theories should only be taught if they relate to successful ones, like the various models of the atom.

Failed theories are useful tools for demonstrating how the process of science works; beyond that, they're fairly useless and could potentially clutter a student's mind with useless points.

And you'd best remember hearing about Lamarck's theory.

Nothing in a science class should be taught as 'true'. Science is about the constant observation and analysis of nature, so there is never really anything that is 'true', simply assesments of observations that are more accurate than others.

That's the point. Evolution has been observed in nature; that makes it a fact, or as close to a fact as you can possibly get in the scientific realm. The theory of evolution is an attempt to explain why and how that observation occurs. When someone says that they don't believe in evolution, what they really mean is that they don't believe that Darwin's theory of evolution can explain the observed process of evolution.

To better get this point across, think about it like this: when Lamarck's theory of evolution was shown to be insufficient, did that make evolution wrong, or just Lamarck's theory to explain evolution?

There is a difference between "this is what 98% of the world thinks, make sure you know it for the test, but if you don't want to believe it then that's your concern" and "This is entirely true and you aren't allowed to believe otherwise."

Again, it seems to me that you are attacking the theory to explain the process, not the process itself. Anyone that claims a theory to be entirely true and not subject to alteration is a fool; or to put it another way, they are religious/dogmatic. There are dogmatic thinkers when it comes to Darwins theory, and they are incorrect in their thinking. However, when it comes to science, one has to assume that the observations you make are correct and thus can be considered facts; if you don't, the whole process of science falls apart. Perhaps in the field of philosophy this may not be the case, but philosophical musing is not for the science classroom.