1 Even if they occur during the commission, they occur with a view to that part of the wrong which either has been done or is yet to be done.
2 Though the scandalous actions might also lead to future wrongs by the principal.
3 In the common law of complicity, the driver of a getaway car would probably be guilty as an accomplice by having ‘aided and abetted’ the burglary. As an aider and abettor he would still be guilty of the principal offence of burglary, but since his action would not be thought of as coming within the legal definition of the offence he would be treated has having assisted rather than committed it.
4 In the common law, an intent to co-operate may be inferred from proof that the accused realized that his conduct would, or would very probably, assist or encourage the principal: National Coal Board v Gamble  1 QB 11,  All ER 203; Clarkson  3 All ER 344,  1 WLR 1402. According to Devil J in Gamble, if a man sells a gun to another which he knows will be used for murder, he cannot escape from guilt as an abettor merely because he sold the gun only for the money and not in order that the victim be killed. Even if the co-operator does not desire the commission of the principal offence, both morality and the common law recognize that intent to assist may be implied by the circumstances. But whether, in a given case, assistance is best characterized as implicitly formal or only material (though still unlawful) depends largely on difficult questions surrounding the distinction between knowledge and intent which have long dogged the philosophy of mind and action.
5 For an egregious example of the idea that there can be such a thing as ‘moral mathematics’, see Parfit, D., Reasons and Persons (Oxford: Oxford University, 1984).
6 See Anscombe, G. E. M., ‘Modern Moral Philosophy’ in her Ethics, Religion and Politics: Philosophical Papers, vol. III (Oxford: Blackwell, 1981), 26–42.
7 The most probable answer is that one generally may not advise the commission of a lesser evil for the general reasons stated above; but that if the lesser evil were already a virtual part of the greater, one could advise that the other person commit it instead. Example: Anna intends to steal £100 from Bertha; Christina, to prevent the theft, advises Anna to steal £50 instead. Here the act of stealing £50 is a virtual part of the act of stealing £100; Anna has already made up her mind to steal from Bertha, so Christina is not acting at all as a cause of theft (or seducer into theft), a fortiori not as a cause of the theft of £50 (or seducer); and Anna thereby prevents the greater evil, namely the theft of £100.
8 See Oderberg, D. S., Moral Theory (Oxford: Blackwell, 2000), ch. 3. See also Chappell, T. D. J., ‘Two Distinctions that Do Make a Difference’, Philosophy 77 (2002), 211–33.
9 If you think the latter is permissible, you can change the example to child pornography.
10 Note: if you do not know the hitch-hiker's purpose until after the event you are an unwitting, and hence not even material co-operator.
11 Should you worry that some people will be scandalized by your behaviour in virtue of not having been informed that you were held at gunpoint? No, since there is no obligation to suffer a great loss (e.g. your own life) just to avoid the scandal of those who rush to judgment (what is sometimes called Pharisaic scandal). The right answer to such people is: ‘If you are scandalized, that's your problem.’
12 Present with qualifications in the common law until its abolition by statute in 1967.
15 What about knowledge by the seller that some wrongful act will be committed, but ignorance as to which? The same considerations would apply to lack of knowledge of the identity of the offence as to lack of knowledge of the identity of the offender. Needless to say, formal co-operation in both cases is impermissible. In common law, intentional co-operation involving lack of knowledge of the identity of the offence is sufficient for liability: DPP for Northern Ireland v Maxwell  All ER 1140; it is difficult to know whether the same would apply to lack of knowledge of the offender.
16 For a defence of realism about intention, see Moral Theory, pp. 110–26.