I have to see the sentences to be able to answer this. I'm happy to help if I can.
This quote means to describe the root of the deprecation of many people to properly conduct an investigation about any subject, and that root is lack of interest. In order to do something right, one must concentrate on that subject alone, ignoring all other distractions, but that can only be achieved if the investigator feels drawn to the subject - meaning they find it interesting.
Lack of interest is what accomplishes to "keep a man in everlasting ignorance...". In the case of ignorance, the investigation might go through, but it will most likely consist of a mindlessly structured compilation of other people's research which the investigator would hardly be able to interpret.
Answer:
Ariana grande is the answer because Ariana grande is famous
Graffiti should be legal because it can used for educational purposes. For example, doing graffiti in a art class. Also, it represents art, which is a big factor in human society. Graffiti shouldnt be legal because some people may jeoperdize other people's property. For example, spray painting on the back wall of a house that isnt permitted. Also with all the symbols that can be made, groups could be formed based on marking territory with graffiti art.