In the trolley example, you aren't choosing to actively cause harm to someone for the sake of the benefit of others. The trolley is going to kill someone. You may, at best, act to reduce the harm done by a process out of your control.
Where the torture example is concerned, one choice involves the active, intentional infliction of pain on someone for the purpose of extracting information that can be used to save lives.
In general, a fairly important principle in ethics is the principle of double effect. I.e.,
1. the action must be in itself good or neutral
2. the action's good effect must be intended, not its evil effect
3. the action's good effect must not be produced by means of the evil effect
4. the action's evil effect must not exceed the good effect in degree
The Trolley is at one end of an extreme. The point of such a hypothetical is that you can adjust any parameter to find peoples' limits.
It could be the case that you don't actually disagree with one another much at all! But if you never address the Trolley problem or similar you will never know.
Kill the villain by pushing him onto the track in front of the train to save the innocents, or not.
It is explicitly asking if you would harm the villain (evil action, evil effect produces good effect).
> whether torture is intrinsically evil, and if not, whether it is ever justifiable
That is exactly the question.
We often make absolute statements ("Killing people is instrinsically evil", "Torture is intrinsically evil") but may find cases where it is justifiable:
- shoot the active shooter (most people agree killing is justified)
- bone marrow donation (causes excruciating pain, willingly accepted by the individual, to save the life/health of another. Most people find this justified, even though it violates "first, do no harm")
- voluntary euthanasia (to involve both torture and killing) - Constant excruciating pain, no hope of a cure. Do you kill the person? Or force them to continue to endure? (People are divided on this one)