Read the following:
Epistemology: The Study of Knowledge http://www.etymonline.com/index.php?term=epistemology
Ontology: The Study of What is Real http://www.etymonline.com/index.php?term=ontology&allowed_in_frame=0
Existentialism: http://www.etymonline.com/index.php?term=existential&allowed_in_frame=0
On the nature of ontological threats:
http://grinding.be/2008/11/18/any-tool-is-a-weapon-if-you-hold-it-right/
http://grinding.be/2012/09/15/ontological-rescue-squad-training-manual-1-know-thyself/
http://grinding.be/2013/03/14/guest-post-damien-williams-on-the-confrontation-of-ontological-terror-squad/
The Nature of Existential Threats:
http://en.wikipedia.org/wiki/Existential_threat#Potential_sources_of_existential_risk
Epistemology: The Study of Knowledge http://www.etymonline.com/index.php?term=epistemology
Ontology: The Study of What is Real http://www.etymonline.com/index.php?term=ontology&allowed_in_frame=0
Existentialism: http://www.etymonline.com/index.php?term=existential&allowed_in_frame=0
On the nature of ontological threats:
http://grinding.be/2008/11/18/any-tool-is-a-weapon-if-you-hold-it-right/
http://grinding.be/2012/09/15/ontological-rescue-squad-training-manual-1-know-thyself/
http://grinding.be/2013/03/14/guest-post-damien-williams-on-the-confrontation-of-ontological-terror-squad/
The Nature of Existential Threats:
http://en.wikipedia.org/wiki/Existential_threat#Potential_sources_of_existential_risk