The use of good guy or bad guy for a person doesn't make much sense.
I'll just list some major facts about Columbus and let you make your own conclusions.
Christopher Columbus believed the world was round. Others during his time didn't believe so. Columbus also thought that the world was smaller than what it actually is, principally because North America and South America were not yet discovered. Columbus went to many people and asked them to fund him, and finally the King and Queen of Spain funded him. When Columbus reached the Americas, he treated the natives harshly. He took their wealth, such as gold, etc, and made the natives slaves. And he brought back the riches of the Caribbean to Spain. Columbus never knew that he had stumbled across an undiscovered land, and instead thought he had reached India, where he was originally going for, and so he called the natives "Indians."
Hope that helped :)
He was a very skilled trapper who was witty and wholesome person.
The Hellenistic scientific concepts are taken from some of the ideas of the Greek philosophers. However, they are more focus on the application of Math and research studies. Many Hellenistic scientific concepts were able to shape geometry as well as other mathematical theories.