Faith vs. Science
The central tension between believing in the Island's purpose and demanding rational explanations. Embodied most directly in the conflict between Locke and Jack.
Key Characters

Jack Shephard
Played by Matthew Fox
A spinal surgeon who becomes the reluctant leader of the crash survivors. Driven by a need to fix everything and everyone. His journey from man of science to man of faith is the emotional spine of the entire series.
The Survivors
John Locke
Played by Terry O'Quinn
A man with a mysterious past who seems reborn on the Island. A hunter, a believer, and a man searching for purpose. His unwavering faith in the Island's meaning drives the show's central philosophical conflict.
The Survivors
Desmond Hume
Played by Henry Ian Cusick
A former Scottish soldier who has been pushing a button in the Swan station every 108 minutes for three years. Driven by his love for Penny Widmore. His time-bending episodes are among the most acclaimed in television history.
The Survivors
Mr. Eko
Played by Adewale Akinnuoye-Agbaje
A Nigerian man of imposing presence and few words who carries a carved scripture stick. A man of deep but complicated faith. His unflinching refusal to apologize for his past makes his confrontation with the Smoke Monster one of the show's most powerful scenes.
The Survivors
Jacob
Played by Mark Pellegrino
The ageless protector of the Island. He has been bringing people to the Island for centuries, searching for someone to prove that humanity is worthy and to replace him. Mark Pellegrino brings a serene, almost unsettling calm to the role of a 2,000-year-old guardian.

Dogen
Played by Hiroyuki Sanada
The enigmatic Japanese leader of the Others at the Temple. A man of discipline and ritual who serves as the last line of defense against the Man in Black. Hiroyuki Sanada brings gravitas and martial arts expertise to a character shrouded in mystery.
The OthersKey Episodes

Pilot (Part 1)
Survivors of a plane crash find themselves on a mysterious tropical island.

Walkabout
Locke goes on a boar hunt. His backstory reveals a life-changing secret.

Exodus (Part 2)
The first season reaches its climax. The raft encounters danger. The Hatch is opened.

Live Together, Die Alone (Part 2)
The season finale. The button's truth is tested. Michael makes his choice.

One of Us
Juliet joins the main camp. Her history with Ben and the Others is explored.

LA X (Part 1)
The final season premiere. Two realities seem to exist simultaneously.

The End (Part 2)
The series finale. Everything that happened, happened.
Related Mysteries
What is the Island?
Introduced in Episode #1
What are the Whispers?
Introduced in Episode #1
What is the Infection?
Introduced in Episode #11
What is Jacob's cabin?
Introduced in Episode #69
What is the four-toed statue?
Introduced in Episode #49