ON ACTING: The Basics
That does not mean every actor should go out and practice indiscriminate sex, or beat up or kill someone. Just because every town has a whore house and a cemetary doesn't mean the actor must literally live there. But they must practice IMAGINING and FEELING those places and situations, and willing to live out those attendant passions in performance.
All other passions pale before sexuality and rage, the colors of red and black. And logically so. Sex and death are the wellspring of life...and its end.
That does not mean all other of life's colors, feelings, are less powerful or important; that there are not brilliant hues of yellow, blue, green and pink; manifestations of sadness, happiness, love and humor that also inspire greatness. But anger and desire, rage and sexuality, drive existence; and drama.
When an actor remains uncomfortable with sex and death (which generally invites a lack of subtlety in their expressive efforts), it limits the actor's character range--and career possibilities.
If you are an actor who is uncomfortable performing roles that demand sexuality and anger, let me ask a question of you: do you like watching love/sex and/or violence/anger scenes in movies? Probably most of you will say yes. So if you do, that means your are not dead to sex and death, just reticent to feel it in public, feel it in stark blaring light of performance.
Life is existentially circumscribed by sex and death; why not embrace it...own it...and learn--through exercises, techniques and practice--to give yourself permission to feel and perform those emotions passionately (hopefully with great subtlety) in front of people. A worthy effort to strive for in the safety of an acting class.